Question

A box contains 100 cards marked from 1 to 100. If one If card is drawn at random from the box, find the probability that it bears :

(i) a single digit number

(ii) a number which is a perfect square

(iii) a number which is divisible by 7

Answer 1

(i) No. of favourable outcomes = 9

No. of all possible outcomes = 100

P(Single digit number)  = 9/100

(ii) Perfect square number are 1, 4,9,16,25,36, 49, 64, 81 and 100

No. of favourable outcomes = 10

.^. . P(Perfect square) = 10/100 = 1/10

(iii) Number divisible by 7 are 7,14,21,28,35,42,49,56,63,70,77,84,91 and 98

No. of favourable outcomes = 14

P(a number divisible by 7) = 14/100