If n objects are arranged in a row, then the number of ways of -Turito

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Easy

Maths-

If n objects are arranged in a row, then the number of ways of selecting three of these objects so that no two of them are next to each other is -

Maths-General

None of these
^{n – 2}C₃
^{n – 3}C₂
^{n – 3}C₃

Answer:The correct answer is: ^{n – 2}C₃

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Between two junction stations A and B there are 12 intermediate stations. The number of ways in which a train can be made to stop at 4 of these stations so that no two of these halting stations are consecutive is -

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The number of rectangles in the adjoining figure is –

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In a model, it is shown that an arch of abridge is semi-elliptical with major axis horizontal. If the length of the base is 9 m and the highest part of the bridge is 3 m from the horizontal, the best approximation of the height of the arch, 2 m from the centre of the base is

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chemistry-

Assertion :this equilibrium favours backward direction.
Reason :is stronger base than $C H subscript 2 end subscript C O O to the power of minus end exponent$

chemistry-General

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A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at $A$ is

fraction numerator 1 over denominator 2 end fraction m v to the power of 2 end exponent equals m g open parentheses 3 minus 1 close parentheses equals 2 m g

v equals square root of 4 g equals 2 square root of g

Vertical component at

A equals 2 square root of g sin invisible function application 30 degree equals square root of g

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at $A$ is

physics-General

fraction numerator 1 over denominator 2 end fraction m v to the power of 2 end exponent equals m g open parentheses 3 minus 1 close parentheses equals 2 m g

v equals square root of 4 g equals 2 square root of g

Vertical component at

A equals 2 square root of g sin invisible function application 30 degree equals square root of g

General

physics-

Two small particles of equal masses start moving in opposite directions from a point $A$ in a horizontal circular orbit. Their tangential velocities are $v$ and $2 v$ , respectively, as shown in the figure. Between collisions, the particles move with constant speeds. After making how many elastic collisions, other than that at $A$ , these two particles will again reach the point $A$

Let initially particle

x

is moving in anticlockwise direction and

y

in clockwise direction
As the ratio of velocities of

x

and

y

particles are

fraction numerator v subscript x end subscript over denominator v subscript y end subscript end fraction equals fraction numerator 1 over denominator 2 end fraction

, therefore ratio of their distance covered will be in the ratio of

2 blank colon 1

. It means they collide at point B

After first collision at B, velocities of particles get interchanged,

i. e

x

will move with

2 v

and particle

y

with

v

Second collision will take place at point C. Again at this point velocities get interchanged and third collision take place at point A
So, after two collision these two particles will again reach the point A

Two small particles of equal masses start moving in opposite directions from a point $A$ in a horizontal circular orbit. Their tangential velocities are $v$ and $2 v$ , respectively, as shown in the figure. Between collisions, the particles move with constant speeds. After making how many elastic collisions, other than that at $A$ , these two particles will again reach the point $A$

physics-General

Let initially particle

x

is moving in anticlockwise direction and

y

in clockwise direction
As the ratio of velocities of

x

and

y

particles are

fraction numerator v subscript x end subscript over denominator v subscript y end subscript end fraction equals fraction numerator 1 over denominator 2 end fraction

, therefore ratio of their distance covered will be in the ratio of

2 blank colon 1

. It means they collide at point B

After first collision at B, velocities of particles get interchanged,

i. e

x

will move with

2 v

and particle

y

with

v

General

physics-

Two small particles of equal masses start moving in opposite directions from a point A in a horizontal circular orbit. Their tangential velocities are $v blank a n d blank 2 v$ respectively, as shown in the figure. Between collisions, the particles move with constant speeds. After making how many elastic collisions, other than that at $A blank$ ,these two particles will again reach The point $A ?$

A s first collision one particle having speed 2v will rotate

240 degree open parentheses o r fraction numerator 4 pi over denominator 3 end fraction close parentheses

while other particle having speed

v blank

will rotate

120 degree open parentheses o r fraction numerator 2 pi over denominator 3 end fraction close parentheses.

At first collision they will exchange their velocities. Now as shown in figure, after two collisions they will again reach at point A.

Two small particles of equal masses start moving in opposite directions from a point A in a horizontal circular orbit. Their tangential velocities are $v blank a n d blank 2 v$ respectively, as shown in the figure. Between collisions, the particles move with constant speeds. After making how many elastic collisions, other than that at $A blank$ ,these two particles will again reach The point $A ?$

physics-General

A s first collision one particle having speed 2v will rotate

240 degree open parentheses o r fraction numerator 4 pi over denominator 3 end fraction close parentheses

while other particle having speed

v blank

will rotate

120 degree open parentheses o r fraction numerator 2 pi over denominator 3 end fraction close parentheses.

At first collision they will exchange their velocities. Now as shown in figure, after two collisions they will again reach at point A.

General

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The trajectory of a particle moving in vast maidan is as shown in the figure. The coordinates of a position $A$ are $open parentheses 0 , 2 close parentheses.$ The coordinates of another point at which the instantaneous velocity is same as the average velocity between the points are

physics-General

General

physics-

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line $O A$ will

When the length of spring is halved, its spring constant will becomes double

open square brackets B e c a u s e blank k proportional to fraction numerator 1 over denominator x end fraction proportional to fraction numerator 1 over denominator L end fraction therefore k proportional to fraction numerator 1 over denominator L end fraction close square brackets

Slope of force displacement graph gives the spring constant

left parenthesis k right parenthesis

of spring
If

k

becomes double then slope of the graph increases

i. e.

graph shifts towards force- axis

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line $O A$ will

physics-General

When the length of spring is halved, its spring constant will becomes double

open square brackets B e c a u s e blank k proportional to fraction numerator 1 over denominator x end fraction proportional to fraction numerator 1 over denominator L end fraction therefore k proportional to fraction numerator 1 over denominator L end fraction close square brackets

Slope of force displacement graph gives the spring constant

left parenthesis k right parenthesis

of spring
If

k

becomes double then slope of the graph increases

i. e.

graph shifts towards force- axis

General

physics-

An intense stream of water of cross-sectional area $A$ strikes a wall at an angle $theta$ with the normal to the wall and returns back elastically. If the density of water is $rho$ and its velocity is $v$ ,then the force exerted in the wall will be

Linear momentum of water striking per second to the wall

P subscript 1 end subscript equals m v equals A v rho blank v equals A v to the power of 2 end exponent blank rho

P subscript r end subscript equals A v to the power of 2 end exponent rho

Now making components of momentum along

x

- axes and

y

-axes. Change in momentum of water per second

equals P subscript i end subscript cos invisible function application theta plus P subscript r end subscript cos invisible function application theta

equals 2 A v to the power of 2 end exponent blank rho cos invisible function application theta

By definition of force, force exerted on the Wall

equals 2 A v to the power of 2 end exponent blank rho cos invisible function application theta

An intense stream of water of cross-sectional area $A$ strikes a wall at an angle $theta$ with the normal to the wall and returns back elastically. If the density of water is $rho$ and its velocity is $v$ ,then the force exerted in the wall will be

physics-General

Linear momentum of water striking per second to the wall

P subscript 1 end subscript equals m v equals A v rho blank v equals A v to the power of 2 end exponent blank rho

P subscript r end subscript equals A v to the power of 2 end exponent rho

Now making components of momentum along

x

- axes and

y

-axes. Change in momentum of water per second

equals P subscript i end subscript cos invisible function application theta plus P subscript r end subscript cos invisible function application theta

equals 2 A v to the power of 2 end exponent blank rho cos invisible function application theta

By definition of force, force exerted on the Wall

equals 2 A v to the power of 2 end exponent blank rho cos invisible function application theta

General

physics-

The potential energy of a particle varies with distance $x$ as shown in the graph.
The force acting on the particle is zero at

F equals fraction numerator negative d U over denominator d x end fraction

it is clear that slope of

U minus x

curve is zero at point

B

and

C

therefore F equals 0

for point

B

and

C

The potential energy of a particle varies with distance $x$ as shown in the graph.
The force acting on the particle is zero at

physics-General

F equals fraction numerator negative d U over denominator d x end fraction

it is clear that slope of

U minus x

curve is zero at point

B

and

C

therefore F equals 0

for point

B

and

C

General

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The number of ways is which an examiner can assign 30 marks to 8 questions, giving not less than 2 marks to any question is -

maths-General

General

maths-

If ⁿC_r denotes the number of combinations of n things taken r at a time, then the expression ⁿC_r+1 + ⁿC_{r –1} + 2 × ⁿC_r equals-

maths-General

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If n objects are arranged in a row, then the number of ways of selecting three of these objects so that no two of them are next to each other is -

None of these
^{n – 2}C₃
^{n – 3}C₂
^{n – 3}C₃

Answer:The correct answer is: ^{n – 2}C₃

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Related Questions to study

Between two junction stations A and B there are 12 intermediate stations. The number of ways in which a train can be made to stop at 4 of these stations so that no two of these halting stations are consecutive is -

Between two junction stations A and B there are 12 intermediate stations. The number of ways in which a train can be made to stop at 4 of these stations so that no two of these halting stations are consecutive is -

The number of non-negative integral solutions of x + y + z  n, where n  N is -

The number of non-negative integral solutions of x + y + z  n, where n  N is -

The number of numbers between 1 and 10¹⁰ which contain the digit 1 is -

The number of numbers between 1 and 10¹⁰ which contain the digit 1 is -

The number of rectangles in the adjoining figure is –

The number of rectangles in the adjoining figure is –

In a model, it is shown that an arch of abridge is semi-elliptical with major axis horizontal. If the length of the base is 9 m and the highest part of the bridge is 3 m from the horizontal, the best approximation of the height of the arch, 2 m from the centre of the base is

In a model, it is shown that an arch of abridge is semi-elliptical with major axis horizontal. If the length of the base is 9 m and the highest part of the bridge is 3 m from the horizontal, the best approximation of the height of the arch, 2 m from the centre of the base is

Assertion :this equilibrium favours backward direction.
Reason :is stronger base than $C H subscript 2 end subscript C O O to the power of minus end exponent$

Assertion :this equilibrium favours backward direction.
Reason :is stronger base than $C H subscript 2 end subscript C O O to the power of minus end exponent$

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at $A$ is

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at $A$ is

The trajectory of a particle moving in vast maidan is as shown in the figure. The coordinates of a position $A$ are $open parentheses 0 , 2 close parentheses.$ The coordinates of another point at which the instantaneous velocity is same as the average velocity between the points are

The trajectory of a particle moving in vast maidan is as shown in the figure. The coordinates of a position $A$ are $open parentheses 0 , 2 close parentheses.$ The coordinates of another point at which the instantaneous velocity is same as the average velocity between the points are

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line $O A$ will

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line $O A$ will

An intense stream of water of cross-sectional area $A$ strikes a wall at an angle $theta$ with the normal to the wall and returns back elastically. If the density of water is $rho$ and its velocity is $v$ ,then the force exerted in the wall will be

An intense stream of water of cross-sectional area $A$ strikes a wall at an angle $theta$ with the normal to the wall and returns back elastically. If the density of water is $rho$ and its velocity is $v$ ,then the force exerted in the wall will be

The potential energy of a particle varies with distance $x$ as shown in the graph.
The force acting on the particle is zero at

The potential energy of a particle varies with distance $x$ as shown in the graph.
The force acting on the particle is zero at

The number of ways is which an examiner can assign 30 marks to 8 questions, giving not less than 2 marks to any question is -

The number of ways is which an examiner can assign 30 marks to 8 questions, giving not less than 2 marks to any question is -

If ⁿC_r denotes the number of combinations of n things taken r at a time, then the expression ⁿC_r+1 + ⁿC_{r –1} + 2 × ⁿC_r equals-

If ⁿC_r denotes the number of combinations of n things taken r at a time, then the expression ⁿC_r+1 + ⁿC_{r –1} + 2 × ⁿC_r equals-

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If n objects are arranged in a row, then the number of ways of selecting three of these objects so that no two of them are next to each other is -

None of these n – 2C3 n – 3C2 n – 3C3

Answer:The correct answer is: n – 2C3

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Related Questions to study

Between two junction stations A and B there are 12 intermediate stations. The number of ways in which a train can be made to stop at 4 of these stations so that no two of these halting stations are consecutive is -

Between two junction stations A and B there are 12 intermediate stations. The number of ways in which a train can be made to stop at 4 of these stations so that no two of these halting stations are consecutive is -

The number of non-negative integral solutions of x + y + z  n, where n  N is -

The number of non-negative integral solutions of x + y + z  n, where n  N is -

The number of numbers between 1 and 1010 which contain the digit 1 is -

The number of numbers between 1 and 1010 which contain the digit 1 is -

The number of rectangles in the adjoining figure is –

The number of rectangles in the adjoining figure is –

In a model, it is shown that an arch of abridge is semi-elliptical with major axis horizontal. If the length of the base is 9 m and the highest part of the bridge is 3 m from the horizontal, the best approximation of the height of the arch, 2 m from the centre of the base is

In a model, it is shown that an arch of abridge is semi-elliptical with major axis horizontal. If the length of the base is 9 m and the highest part of the bridge is 3 m from the horizontal, the best approximation of the height of the arch, 2 m from the centre of the base is

Assertion :this equilibrium favours backward direction.Reason :is stronger base than

Assertion :this equilibrium favours backward direction.Reason :is stronger base than

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at is

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at is

The trajectory of a particle moving in vast maidan is as shown in the figure. The coordinates of a position are The coordinates of another point at which the instantaneous velocity is same as the average velocity between the points are

The trajectory of a particle moving in vast maidan is as shown in the figure. The coordinates of a position are The coordinates of another point at which the instantaneous velocity is same as the average velocity between the points are

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line will

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line will

An intense stream of water of cross-sectional area strikes a wall at an angle with the normal to the wall and returns back elastically. If the density of water is and its velocity is ,then the force exerted in the wall will be

An intense stream of water of cross-sectional area strikes a wall at an angle with the normal to the wall and returns back elastically. If the density of water is and its velocity is ,then the force exerted in the wall will be

The potential energy of a particle varies with distance as shown in the graph.The force acting on the particle is zero at

The potential energy of a particle varies with distance as shown in the graph.The force acting on the particle is zero at

The number of ways is which an examiner can assign 30 marks to 8 questions, giving not less than 2 marks to any question is -

The number of ways is which an examiner can assign 30 marks to 8 questions, giving not less than 2 marks to any question is -

If nCr denotes the number of combinations of n things taken r at a time, then the expression nCr+1 + nCr –1 + 2 × nCr equals-

If nCr denotes the number of combinations of n things taken r at a time, then the expression nCr+1 + nCr –1 + 2 × nCr equals-

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None of these
^{n – 2}C₃
^{n – 3}C₂
^{n – 3}C₃

Answer:The correct answer is: ^{n – 2}C₃

The number of numbers between 1 and 10¹⁰ which contain the digit 1 is -

The number of numbers between 1 and 10¹⁰ which contain the digit 1 is -

Assertion :this equilibrium favours backward direction.
Reason :is stronger base than $C H subscript 2 end subscript C O O to the power of minus end exponent$

Assertion :this equilibrium favours backward direction.
Reason :is stronger base than $C H subscript 2 end subscript C O O to the power of minus end exponent$

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at $A$ is

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at $A$ is

The trajectory of a particle moving in vast maidan is as shown in the figure. The coordinates of a position $A$ are $open parentheses 0 , 2 close parentheses.$ The coordinates of another point at which the instantaneous velocity is same as the average velocity between the points are

The trajectory of a particle moving in vast maidan is as shown in the figure. The coordinates of a position $A$ are $open parentheses 0 , 2 close parentheses.$ The coordinates of another point at which the instantaneous velocity is same as the average velocity between the points are

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line $O A$ will

The force required to stretch a spring varies with the distance as shown in the figure. If the experiment is performed with above spring of half length, the line $O A$ will

An intense stream of water of cross-sectional area $A$ strikes a wall at an angle $theta$ with the normal to the wall and returns back elastically. If the density of water is $rho$ and its velocity is $v$ ,then the force exerted in the wall will be

An intense stream of water of cross-sectional area $A$ strikes a wall at an angle $theta$ with the normal to the wall and returns back elastically. If the density of water is $rho$ and its velocity is $v$ ,then the force exerted in the wall will be

The potential energy of a particle varies with distance $x$ as shown in the graph.
The force acting on the particle is zero at

The potential energy of a particle varies with distance $x$ as shown in the graph.
The force acting on the particle is zero at

If ⁿC_r denotes the number of combinations of n things taken r at a time, then the expression ⁿC_r+1 + ⁿC_{r –1} + 2 × ⁿC_r equals-

If ⁿC_r denotes the number of combinations of n things taken r at a time, then the expression ⁿC_r+1 + ⁿC_{r –1} + 2 × ⁿC_r equals-