Question

There are 80 cards numbered from 1 to 80. One card is drawn at random from them. Find the probability that the number on the selected card is not divisible by 8.

Answer 1

Total number of possible outcomes = 80.

Numbers divisible by 8 are 8, 16, 24, 32, 40, 48, 56, 64, 72, and 80.

There are total 10 numbers which are divisible by 8. Number of numbers (not divisible by 8)

= 80 −10 = 70

Number of favourable outcomes = 70

Required probability is

P(E) = `("Number of favourable outcomes")/("otal number of possible outcomes")`

= `70/80`

= `7/8`

Therefore, the probability that the number on the selected card is not divisible by 8 is `7/8`.