2n boys are randomly divided into two subgroups containing n boys each. The probability that the two tallest boys are in different groups is

2n boys are randomly divided into two subgroups containint n boys each. The probability that eh two tallest boys are in different groups is n//(2n-1) b. (n-1)//(2n-1) c. (n-1)//4n^2 d. none of these

There are only two women among 20 persons taking part in a pleasure trip. The 20 persons are divided into two groups, each group consisting of 10 person. Then the probability that the two women will be in the same group is 9//19 b. 9//38 c. 9//35 d. none

Fourteen numbered balls (1, 2, 3, …, 14) are divided in 3 groups randomly. Find the probability that the sum of the numbers on the balls, in each group, is odd.

A candidate is required to answer 7 questions out of 12 questions, which are divided into two groups, each containing 6 questions. He is not permitted to attempt more than 5 questions from each group. Number of ways choosing 7 questions is

Three boys and two girls stand in a queue. The probability, that the number of boys ahead is at least one more than the number of girls ahead of her, is

10 different books and 2 different pens are given to 3 boys so that each gets equal number of things. The probability that the same boy does not receive both the pens is

If the papers of 4 students randomly đistributed for checking among 7 teachers, then the probability that all the 4 papers are checked by exactly 2 teachers is n i m where n, m are 'natural numbers and H C F(n, m)=1 . Then number of positive divisors of (n+m) is

m balls are distributed among a boys and b girls. Prove that the probability that odd numbers of balls are distributed to boys is ((b+a)^m - (b+a)^m)/ (2 (a+b)^m) .

2^n players of equal strength are playing a knock out tournament. If they are paired at randomly in all rounds, find out the probability that out of two particular players S_1a n dS_2, exactly one will reach in semi-final (n in N ,ngeq2)dot