A. -1
B. 1
C. -2
D. 2
A is one of 6 horses entered for a race and is to be ridden by one of two jockeysP and Q. It is 2 to 1 that P rides A, in which case all the horses are likely to win. If Q rides A, his chance is tribled. The probability of A’s winning is
5 different engineering, 4 different mathematics and 2 different chemistry books are placed in a shelf at random. The probability that the books of each kind are all together is
In a class of 125 students 70 passed in Mathematics and 55 in statistics and 30 in both. The probability that a student, selected at random from the class, has passed in only one subject is
A man is known to speak the truth 2 out of 3 times. He throws a die and reports that it is a six. The probability that it is actually a five is
A bag contains 4 green, 6 black and 7 white balls. A ball is drawn at random .The probability that it is either black ball or a white ball is
The sum of the distances of any point on the ellipse 3x2+4y2=24 from its foci is
One ticket is selected at random from 100 tickets numbered 00,01,02,...99. Suppose A and B are the sum and product of the digits found on the ticket. Then P(A=7 | B=0) is given by
The probability that the roots of equation x2+nx+1/2+n/2=0 are real ,where n ε N such that n ≤ 5, is
A and B are two independent events. If the probability that both A and B occur is 1/20 and the probability that neither of them occurs is 3/5, then P(A),P(B)=