Maths-
General
Easy
Question
A seven digit number is in form of abcdefg (g, f, e, etc. are digits at units, tens, hundred place etc.) where a < b < c < d > e > f > g. The number of such numbers are
- 1981
- 2009
- 1560
- 1870
The correct answer is: 1560
Cases : i) If d = 6 then seven digit numbers possible are = 5C3. 3C3
[as a,b,c can be choosen from 1,2,3,4 or 5 & similarly e,f,g can be choosen from the unused 2 digit which are less than 6 & 0 can be used]
ii) If d = 7 then numbers possible =,
iii) If d = 8 then numbers possible = 
iv) If d = 9 then numbers possible = 
Add all cases
Related Questions to study
maths-
Number of ways in which 25 identical balls can be distributed among Ram, Shyam, Sunder and Ghanshyam such that atleast 1, 2, 3, and 4 balls are given to Ram, Shyam, Sunder and Ghanshyam respectively, is-
Number of ways in which 25 identical balls can be distributed among Ram, Shyam, Sunder and Ghanshyam such that atleast 1, 2, 3, and 4 balls are given to Ram, Shyam, Sunder and Ghanshyam respectively, is-
maths-General
maths-
One hundred identical marbles are to be distributed to three children so that each gets atlest 20 and no two get equal number. The number of ways of doing this is -
One hundred identical marbles are to be distributed to three children so that each gets atlest 20 and no two get equal number. The number of ways of doing this is -
maths-General
maths-
The number of five-digit telephone numbers having at least one of their digits repeated is
The number of five-digit telephone numbers having at least one of their digits repeated is
maths-General
maths-
The maximum value of P such that 3P divides 99 × 97 × 95 × .... × 51 is-
The maximum value of P such that 3P divides 99 × 97 × 95 × .... × 51 is-
maths-General
maths-
If 
for 
, then 
If for , then
maths-General
maths-
The largest value of r satisfying inequality 20Cr 
20Cr – 1 is -
The largest value of r satisfying inequality 20Cr 20Cr – 1 is -
maths-General
maths-
A double decker bus can accommodate (u + 
) passengers, u in the upper deck and in the lower deck. The number of ways in which the (u + ) passengers can be distributed in the two decks, if r (
) particular passengers refuse to go in the upper deck and S(
u) refuse to sit in the lower deck, is -
A double decker bus can accommodate (u + ) passengers, u in the upper deck and in the lower deck. The number of ways in which the (u + ) passengers can be distributed in the two decks, if r () particular passengers refuse to go in the upper deck and S(u) refuse to sit in the lower deck, is -
maths-General
maths-
Domain of f(x) = log10(log10(1 + x3)) is -
Domain of f(x) = log10(log10(1 + x3)) is -
maths-General
chemistry-
The correct orders about compounds I and II are:
i) 
ii) 
The correct orders about compounds I and II are:
i)
ii)
chemistry-General
chemistry-
Which of the following is correct method for separating a mixture of following compounds?
Which of the following is correct method for separating a mixture of following compounds?
chemistry-General
chemistry-
The order in which the reagent must be used to separate the compound I - IV is:
The order in which the reagent must be used to separate the compound I - IV is:
chemistry-General
chemistry-
Decreasing order of solubility of following compounds is:
i) 
ii) 
iii) 
iv) 
Decreasing order of solubility of following compounds is:
i)
ii)
iii)
iv)
chemistry-General
chemistry-
Which of the following statement is correct about tropolone?
Which of the following statement is correct about tropolone?
chemistry-General
chemistry-
In which case first has higher solubility than second?
I) Phenol, Benzene
II) Nitrobenzene, Phenol
III) o–Hydroxybenzaldehyde, p–Hydroxy benzaldehyde
IV) CH3CHO, CH3–O–CH3
V) o–Nitrophenol, p–Nitrophenol
VI) 
In which case first has higher solubility than second?
I) Phenol, Benzene
II) Nitrobenzene, Phenol
III) o–Hydroxybenzaldehyde, p–Hydroxy benzaldehyde
IV) CH3CHO, CH3–O–CH3
V) o–Nitrophenol, p–Nitrophenol
VI)
chemistry-General
chemistry-
Arrange the following in decreasing order of their solubility in water
Arrange the following in decreasing order of their solubility in water
chemistry-General
