Three students appear in an examination of Mathemetics. The probabilities of their success are `(1)/(3), (1)/(4) and (1)/(5)`, respectively. If the probability of success of atleast two is `(lambda)/(1)`, then the value of `lambda` is

Three students appear at an examination of mathematics. The probability of their success are 1/3,1/4,1/5 respectively. Find the probability of success of at least two.

Three persons work independently on a problem. If the respective probabilities that they will solve it are 1/3, 1/4 and 1/5, then find the probability that none can solve it.

Three persons work independently on a problem. If the respective probabilities that they will solve it are 1/3, 1/4 and 1/5, then find the probability that not can solve it.

The probabilities that three children can win a race are 1/3,1/4 and 1/5 . Find the probability that any one can win the race.

In a series of three trials , the probability of two successes is 9 times the probability of three successes . Then the probability of success in each trial is :

A student appears for tests I, II and III. The student is considered successful if he passes in tests I, II or III or all the three. The probabilities of the Student passing in tests I,II and III are m, n and 1/2 respectively. If the probability of the student to be successful is 1/2 , then which one of the following is correct? (a) m (1+n)=1 (B) n (1+m) =1 (C) m=1 (D) mn=1

A problem is given to three students whose chances of solving it are 1/4, 1/5 and 1/3 respectively. Find the probability that the problem is solved.

IF the mean and the variance of a binomial distribution are 4 and 3 respectively ,then the probability of six successes is

IF the mean and the variance of a binomial distribution are 4 and 3 respectively , then the probability of six successes is

if mu_21 is 1.5, then find the value of lambda_1/lambda_2.