A bag is contains 50 coins and each coin is marked from 51 to 100. One coin is picked at random. The probability that the number on the coin is not a prime number, is
Total number of coins = 50
∴ Total number of outcomes = 50
prime numbers are = 53, 59, 61, 67, 71, 73, 79, 83, 89, 97
P(prime numbers) = 
∴ P(not prime numbers) = 
9