Question

A bag contains twenty Rs 5 coins, fifty Rs 2 coins and thirty Re 1 coins. If it is equally likely that one of the coins will fall down when the bag is turned upside down, what is the probability that the coin:

(i) will be a Re 1 coin? 

(ii) will not be a Rs 2 coin? 

(iii) will neither be a Rs 5 coin nor be a Re 1 coin?

Answer 1

(ii) Number of favorable outcomes for not a Rs. 2 coins = number of favorable outcomes for Re. 1  or Rs. 5 coins = 30 + 20 = 50 = n(E)

(iii) number of favorable outcomes for neither Re 1 nor Rs. 5 coins = Number of favorable outcomes  for Rs. 2 coins = 50 = n(E)