If the papers of 4 students can be checked by any one of the 7 teachers, then the probability that all the 4 papers are checked by exactly 2 teachers is a.`2//7` b. `12//49` c. `32//343` d. none of these

If the papers of 4 students can be checked by any one of the 7 teachers, then the probability that all the 4 papers are checked by exactly 2 teachers is 2//7 b. 12//49 c. 32//343 d. none of these

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

A father has 3 children with at least one boy. The probability that he has 2 boys and 1 girl is a. 1//4 b. 1//3 c. 2//3 d. none of these

If n integers taken at random are multiplied together , then the probability that the last digit of the product is 1, 3, 7, or 9 is a. 2^n//5^n b. 4^n-2^n//5^n c. 4^n//5^n d. none of these

Five different marbles are placed in 5 different boxes randomly. Then the probability that exactly two boxes remain empty is (each box can hold any number of marbles) 2//5 b. 12//25 c. 3//5 d. none of these

The numbers (a ,b ,c) are selected by throwing a dice thrice, then the probability that (a ,b ,c) are in A.P. is a. 1//12 b. 1//6 c. 1//4 d. none of these

The sum of two positive quantities is equal to 2ndot the probability that their product is not less than 3/4 times their greatest product is 3//4 b. 1//4 c. 1//2 d. none of these

If the integers m and n are chosen at random between 1 and 100, then the probability that a number of the form 7^m+7^n is divisible by 5, equals (a) 1/4 (b) 1/7 (c) 1/8 (d) 1/49

Five different games are to be distributed among 4 children randomly. The probability that each child get at least one game is a. 1//4 b. 15//64 c. 5//9 d. 7//12

The number of different seven-digit numbers that can be written using only the three digits 1, 2, and 3 with the condition that the digit 2 occurs twice in each number is a. 2P_5 2^5 b. 7C_2 2^5 c. 7C_2 5^2 d. none of these