In a lottery of 50 tickets numbered 1 to 50, two tickets are drawn simultaneously. Find the probability that: (a) both the tickets drawn have prime numbers. (b) none of the tickets drawn has prime number. (c) one ticket has prime number.

Explanation

`n(S)=.^50C_2`

`n(B)=.^35C_2`

`P(B)=(.^35C_2)/(.^50C_2)`

`P(C)=(.^15C_1*.^35C_1)/(.^50C_2)`.