Question 22 (OR 1st question) A lot of 25 bulbs contain 5 defective ones. One bulb is drawn at random from the lot. What is the probability that the bulb is good.
Given
Total number of bulbs = 25
Total number of defective bulbs = 5
So,
Total Number of good bulbs = 25 – 5 = 20
Now,
P (getting a good bulb) = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑔𝑜𝑜𝑑 𝑏𝑢𝑙𝑏𝑠)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑢𝑙𝑏𝑠)
= 20/25
= 𝟒/𝟓

CBSE Class 10 Sample Paper for 2020 Boards - Maths Basic

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.