Check sibling questions

Question 1 - Past Year MCQ - Chapter 14 Class 10 Probability

Last updated at May 29, 2023 by

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

Slide1.JPG

Slide2.JPG

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Book a free demo

Transcript

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 are… 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) = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑟𝑖𝑚𝑒 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 𝑙𝑒𝑠𝑠 𝑡ℎ𝑎𝑛 23)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟𝑠) = 8/90 = 𝟒/𝟒𝟓 So, the correct answer is (C)

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.