Probability Tes...

There are n urns each containing (n + 1) balls such that the i^th urn contains ‘i’ white balls and (n + 1 – i) red balls. Let u_i be the event of selecting i^th urn, I = 1, 2, 3,…,n and W denotes the event of getting a white balls.

A box contains 15 tickets numbered 1, 2, …, 15. Seven tickets are drawn at random one after the other with replacement. The probability that the greatest number on a drawn ticket is 9 is

Two square are chosen at random on a chess-board. The probability that they have a side in common is

The probability that a certain beginner t golf gets a good shot if he uses the correct club is 1/3 and the probability of a good shot which an incorrect club is ¼. In his bag are 5 different clubs, only one of which is correct for the shot in question. If he chooses a club at random and takes a stroke, then the probability that he gets a good shot is

A man alternately tosses a coins and throws a dice beginning with the coin. The probability that he gets a head in the coin before he gets a 5 or 6 in the dice is

Two persons ‘A’ and ‘B’ have respectively n + 1 and n coin which they toss simultaneously. Then, the probability that A will have more heads than B is

Two dice are rolled one after the other. The probability that the number on the first is smaller than the number on the second is

A and B toss a fair coin each simultaneously 50 times. The probability that both of them will not get tail at the same toss is

Three distinct numbers are selected from first 100 natural numbers. The probability that the three numbers are divisible by 2 and 3 is