MEDIUM
JEE Main/Advance
IMPORTANT
Earn 100

The number of ways in which five vowels of English alphabets and ten decimal digits can be placed in a row such that between any two vowels, odd number of digits are placed and both end places are occupied by vowels, is 20b!5!. Then evaluate b.

Important Questions on Permutation and Combination

HARD
JEE Main/Advance
IMPORTANT
The number of integers which lie between 1 and 106 and which have the sum of the digits equal to 12 is N then N-6000 is equal to
MEDIUM
JEE Main/Advance
IMPORTANT
The number of ways in which 8 non-identical apples can be distributed among 3 boys such that every boy should get atleast 1 apple & atmost 4 apples is N then N60 is equal to
EASY
JEE Main/Advance
IMPORTANT
in a hockey series between team X and Y, they decide to play till a team wins '10' match. Then the number of ways in which a team X wins is Cm202 then m is equal to
HARD
JEE Main/Advance
IMPORTANT
Three ladies have brought one child each for admission to a school. The principal wants to interview the six persons one by one subject to the condition that no mother is interviewed before her child. Then find the number of ways in which interviews can be arranged.
EASY
JEE Main/Advance
IMPORTANT
In a shooting competition, a man can score 0, 2 or 4 points for each shot. Then the number of different ways in which he can score 14 points in 5 shots is
MEDIUM
JEE Main/Advance
IMPORTANT
Six persons A, B, C, D, E and F are to be seated at a circular table. The number of ways this can be done if A must have either B or C on his right and B must have either C or D on his right is
EASY
JEE Main/Advance
IMPORTANT
The number of permutations which can be formed out of the letters of the word "SERIES" taking three letters together is
HARD
JEE Main/Advance
IMPORTANT
A box contains 6 balls which may be all of different colours or three each of two colours or two each of three different colours. The number of ways of selecting 3 balls from the box (if ball of same colour are identical) is