Two friends `Aa n dB` have equal number of daughters. There are three cinema tickets which are to be distributed among the daughters of `Aa n dB` . The probability that all the tickets go to the daughters of `A` is 1/20. Find the number of daughters each of them have.

Two different families A and B are blessed with equal number of children. There are 3 tickets to be distributed amongst the children of these families so that no child gets more than one ticket. If the probability that all the tickets go to children of the family B is (1)/(12) then the number of children in each family is :

Out of 2n tickets numbered 1,2,......,2n three are chosen at random.The probability that the numbers on them are in A.P.is

In a lottery of 100 tickets numbered 1 to 100 two tickets are drawn simultaneously . Find the probabilty that both the ticktets drawn have prime numbers.

n different toys have to be distributed among n children.Find the number of ways in which these toys can be distributed so that exactly one child gets no toy.

n different toys have to be distributed among n children.Find the number of ways in which these toys can be distributed so that exactly one child gets no toy.

A bag contains 20 tickets numbered 1 to 20. Two tickets are drawn at random. Find the probability that both the numbers on the ticket are prime.

A bag contains tickets numbered from 1 to 20. Two tickets are drawn.find the probability that i.both the tickets have prime numbers on them ii.on one there is a prime number and on the other there is a multiple of 4.