### Question

There are 3 letters and 3 addressed envelopes corresponding to them. The number of ways in which the letters be placed in the envelopes so that no letter is in the right envelope is :

- 5
- 3
- 1
- 2

#### The correct answer is: 2

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Grade*

### Related Questions to study

#### Match Column - I with Column - II and select the correct option from the codes give below.

#### Match Column - I with Column - II and select the correct option from the codes give below.

The sum of all the numbers formed by taking all the digits from 3,4,5,6,7 is:

The sum of all the numbers formed by taking all the digits from 3,4,5,6,7 is:

The sum of all the numbers formed by taking all the digits from 2,3,4,5 is:

The number of numbers having 3 in the unit place= 3! =6

The number of numbers having 4 in the unit place= 3! =6

The number of numbers having 5 in the unit place= 3! =6

So the sum of the digits in the unit place of all the numbers=

=12+18+24+30

=84

Similarly the sum of the digits of all the numbers in each of the other places=84

The required sum =

=84(1000+100+10+1)

=84

=93324

The sum of all the numbers formed by taking all the digits from 2,3,4,5 is:

The number of numbers having 3 in the unit place= 3! =6

The number of numbers having 4 in the unit place= 3! =6

The number of numbers having 5 in the unit place= 3! =6

So the sum of the digits in the unit place of all the numbers=

=12+18+24+30

=84

Similarly the sum of the digits of all the numbers in each of the other places=84

The required sum =

=84(1000+100+10+1)

=84

=93324

#### The number of constant mappings from to is

#### The number of constant mappings from to is

#### The number of many one functions from is

#### The number of many one functions from is

#### The number of into functions that can be defined from is

#### The number of into functions that can be defined from is

A body moving with velocity v has momentum and kinetic energy numerically equal. What is the value of v?

A body moving with velocity v has momentum and kinetic energy numerically equal. What is the value of v?

The graph between the resistive force F acting on a body and the distance covered by the body is shown in figure. The mass of the body is 25KG and initial velocity is 2 m/s. When the distance covered by the body is 4km, its kinetic energy would be

The graph between the resistive force F acting on a body and the distance covered by the body is shown in figure. The mass of the body is 25KG and initial velocity is 2 m/s. When the distance covered by the body is 4km, its kinetic energy would be

The number of onto functions that can be defined from A={a,b,c,d,e} to {1,2} is

The number of onto functions that can be defined from A={a,b,c,d,e} to {1,2} is

The momentum of a body increases by 20%. The percentage increase in its kinetic energy is

The momentum of a body increases by 20%. The percentage increase in its kinetic energy is

Two spheres A and B of masses M_{1} and M_{2} respectively collide. A is at rest initially and B is moving with velocity V along X-axis. After collision has a velocity in a direction perpendicular to the original direction. The mass moves after collision in the direction

Two spheres A and B of masses M_{1} and M_{2} respectively collide. A is at rest initially and B is moving with velocity V along X-axis. After collision has a velocity in a direction perpendicular to the original direction. The mass moves after collision in the direction

A block of mass 10 kg slides down a rough slope which is inclined at to the horizontal. The coefficient of sliding friction is 0.30. When the block has slide 5 m, the work done on the block by the force of friction is nearly

A block of mass 10 kg slides down a rough slope which is inclined at to the horizontal. The coefficient of sliding friction is 0.30. When the block has slide 5 m, the work done on the block by the force of friction is nearly

Two identical cylindrical vessels with their bases at same level each contains a liquid of density . The height of the liquid in vessel is h_{1} and that in the other vessel is h_{2}. The area of either base is A. The work done by gravity in equalizing the levels when the two vessels are connected, is

Two identical cylindrical vessels with their bases at same level each contains a liquid of density . The height of the liquid in vessel is h_{1} and that in the other vessel is h_{2}. The area of either base is A. The work done by gravity in equalizing the levels when the two vessels are connected, is

The number of injections from Set - A containing 5 elements to a Set -B containing 6 elements is

The number of injections from Set - A containing 5 elements to a Set -B containing 6 elements is

Two bodies moving towards each other collide and move away in opposite directions. There is some rise in temperature of bodies because a part of the kinetic energy is converted into

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