Question

Cards with numbers 1,2,3,....100 are placed in a box and mixed thoroughly. One card is drawn .What is the probability that the card drawn is :
(i)A prime number less than 30?
(ii)A multiple of 5 and 7?
(iii)A multiple of 5 or 7?

Answer 1

(1) Between 1 and 30, there are eight prime numbers. So, the probability of getting a prime number = no. of events/no. of possibilities

= 8/100 = 2/25=0.08

(2) Multiples of 5 between 1 and 100 are 20. Multiples of 7 are 19. So probability = 20+19/100 = 39/100 = 0.39

(3) Probability of getting a multiple of 5 is 20/100 =0.2

Probability of getting a multiple of 7 is 19/100 = 0.19