Three persons hit a target with probability `1/2,1/3` and `1/4` respectively. If each one shoot at the target once,
if only one of them hits the target what is the probability that it was the first person ?

Three persons hit a target with probability 1/2,1/3 and 1/4 respectively. If each one shoot at the target once, find the probability that exactly one of them hits the target

Three persons hit a target with probabilities (1/2) , (1/3) and (1/4) respectively. If each one shoots at the target once, (i) find the probaility that exactly one of them hits the target, (ii) if only one of them hits the target what is the probability that it was the first person?

Two different digits are selected at random from the digits 1 through 9 If 3 is one of the digits selected, what is the probability that the sum is even?

Two different digits are selected at random from the digits 1 through 9 If 3 is one of the digits selected, what is the probability that the sum is odd?

A laboratory blood test is 99% effective in detecting a certain disease,when it is infact present. However, the test also yields a false positive result for 0.5% of the healthy person tested (ie. if a healthy person is tested, then with probability 0.005, the test will imply he has the disease). If 0.1% of the population actually has the disease, then what is the probability that a person has disease, given that his test result is positive?