Cards marked with numbers 13, 14, 15, …, 60 are placed in a box and mixed thoroughly. One card is drawn at random from the box. Find the probability that the number on the card drawn is
(i) divisible by 5
(ii) a perfect square number.
Cards marked with numbers 13, 14, 15, …, 60 are placed in a box and mixed thoroughly. One card is drawn at random from the box. Find the probability that the number on the card drawn is
(i) divisible by 5
(ii) a perfect square number.

Solution:

The possible outcomes are {13,14,15,…60}

Number of possible outcomes = 48

(i) Let E be the event of getting the number on the card is divisible by 5.

Outcomes favourable to E are {15,20,25,30,35,40,45,50,55,60}

Number of favourable outcomes = 10

P(E) = 10/48 = 5/24

Hence the probability of getting the number on the card is divisible by 5 is 5/24.

(ii) Let E be the event of getting the number on the card is a perfect square number.

Outcomes favourable to E are {16,25,36,49}

Number of favourable outcomes = 4

P(E) = 4/48 = 1/12

Hence the probability of getting the number on the card is a perfect square is 1/12.