Question

1. The probablity of getting exactly 2 tails in 6 tosses of a fair coin?

2. 3 dice are rolled simultaneously the probablity that the sum of the numbers on them is 16 ?

Answer 1

1.
TTHHHH
like this we can write in C(6,2) ways =15
therefore n(A)=15
n(S)=2^6 =64
finally P(A) =15/64

2.
Sum of 16 can be achieved in following ways
6,6,4---Total cases = 3!/2! = 3
6,5,1---Total cases = 3!= 6


Total cases = 6+3=9

Probability = 9* (1/6 * 1/6 * 1/6) = 9/216