There are 10 prizes, five A's, there B's, and two C's placed in identical sealed envelopes for the top 10 contestants in a mathematics contest. The prizes are awarded by allowing winners to select an envelope at random from those remaining. When the 8th contestant goes to select the prize, the probability that the remaining three prizes are one A, one B and one C is

There are 10 prizes, five As, there Bs and two Cs, placed in identical sealed envelopes for the top 10 contestants in a mathematics contest. The prizes are awarded by allowing winners to select an envelope at random from those remaining. Then the 8th contestant goes to select the prize, the probability that the remaining three prizes are once Aa n dB and one C is 1//4 b. 1//3 c. 1//12 d. 1//10

One mapping is selected at random from all mappings of the set S={1,2,3,.... n} into itself. If the probability that the mapping is one-one is 3/32, then the value of n is 2 b. 3 c. 4 d. none of these

A committee of two persons is selected from two men and two women. What is the probability that the committee will have (a) no man? (b) one man? (c) two men?

The same 20 contestants, on each of 3 days, answered 5 questions in order to win a prize. Each contestant received 1 point for each correct answer. The number of contestants receiving a given score on each day is shown in the table above. No contestant received the same score on two different days. If a contestant is selected at random, what is the probability that the selected contestant received a score of 5 on Day 2 or Day 3, given that the contestant received a score of 5 on one of the three days?

A three-digit number is selected at random from the set of all three-digit numbers. The probability that the number selected has all the three digits same is 1//9 b. 1//10 c. 1//50 d. 1//100

Two persons A and B take turns in throwing a pair of dice. The first person to throw 9 from both dice will be awarded the prize. If A throws first, then the probability that B wins the game is 9//17 b. 8//17 c. 8//9 d. 1//9

Number 1, 2, 3, ...100 are written down on each of the cards A, B, and C. One number is selected at random from each of the cards. Then find the probability that the numbers so selected can be the measures (in cm) of three sides of right-angled triangles, no two of which are similar.

Suppose we have four boxes A,B,C and D containing coloured marbles as given below :One of the boxes has been selected at random and a single marble is drawn from it. If the marble is red, what is the probability that it was drawn from box A? box B?, box C?

A box contains 24 identical balls of which 12 are white and 12 are black. The balls are drawn at random from the box one at a time with replacement. The probability that a white ball is drawn for the 4th time on the 7th draw is (a) 5/64 (b) 27/32 (c) 5/32 (d) 1/2

A box contains 24 identical balls of which 12 are white and 12 are black. The balls are drawn at random from the box one at a time with replacement. The probability that a white ball is drawn for the 4th time on the 7th draw is (a) 5/64 (b) 27/32 (c) 5/32 (d) 1/2