Probability Distribution - AS level - CAMBRIDGE MATHS

When a scout group of 8 juniors and 12 seniors meets on a Monday evening, one scout is randomly selected to hoist a flag. Let the variable X represent the number of juniors selected over n consecutive Monday evenings. (a) By drawing up the probability distribution table for X, or otherwise, show that E(X )=1.2 when n=3 . (b) Find the number of Monday evenings over which 14 juniors are expected to be selected to hoist the flag.