Box 1 contains 30 cards numbered 1 to 30 and Box 2 contains 20 cards numbered 31 to 50 . A box is selected at random and a card is drawn from it. The number on the card is found to be a non-prime number. The probability that the card was drawn from Box 1 is

Step-by-step solution

P B 1 = 1 2 = P B 2 Box B 1 have 20 non-prime numbers 1 ,   4 ,   6 ,   8 ,   9 ,   10 ,   12 ,   14 ,   15 ,   16 ,   18 ,   20 ,   21 ,   22 ,   24 ,   25 ,   26 ,   27 ,   28 ,   30 ⇒ P N P / B 1 = 20 30 Box B 1 have 15 non-prime numbers 32 ,   33 ,   34 ,   35 ,   36 ,   38 ,   39 ,   40 ,   42 ,   44 ,   45 ,   46 ,   48 ,   49 ,   50 ⇒