 True/False  MCQ 
Easy  300  500

Difficult  200  400 
Total = 1400, therefore n(S) = 1400 Let A = event of getting easy question B = event of getting multiple choice question.
we know that
If E and F are independent, then P(E/F) = P(E) and P(F/E) = P(F)
P (E ∩ F) = P (E) P (F).