Question 1
A box contains 90 discs, numbered from 1 to 90. If one disc is drawn at random from the box, the probability that it bears a prime-number less than 23, is:
(a) 7/90 (b) 10/90
(c) 4/45 (d) 9/89
Last updated at Dec. 16, 2024 by Teachoo
Question 1 A box contains 90 discs, numbered from 1 to 90. If one disc is drawn at random from the box, the probability that it bears a prime-number less than 23, is: (a) 7/90 (b) 10/90 (c) 4/45 (d) 9/89 Total number of disks = 90 Prime number less than 23 areβ¦ 2, 3, 5, 7, 11, 13, 17, 19 Number of prime numbers less than 23 = 8 Thus, P(getting a prime number less than 23) = (ππ’ππππ ππ πππππ ππ’πππππ πππ π π‘βππ 23)/(πππ‘ππ ππ’πππππ ) = 8/90 = π/ππ So, the correct answer is (C)