31.
Cards numbered 11 to 60 are kept in a box. If a card is drawn at random from the box,
Find the probability that the number on the drawn card is (1) a perfect square number
(ii) a prime number less than 20 (iii) divisible by 7 (iv) a composite number.
Answers
Step-by-step explanation:
Total no. of cards : 50 (60 - 11 + 1)
Perfect sqs from 11-60 : 16, 25, 36, 49
Thus no of perfect sqs in box : 4
Probability = No. of favourable outcomes /
No. of total outcomes
= 4/50
= 2/25
Prime numbers less the 20 in box : 11, 13, 17, 19
Thus no. of prime numbers in box : 4
Probability = 4 / 50
= 2 / 25
Numbers divisible by 7 in box : 14, 21, 28, 35, 42, 49, 56
No. of numbers divisible by 7 in the box : 7
Probability = 7 / 50
Composite numbers in box : 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 60
No. of composite nos in box = 37
Probability = 37 / 50