CBSE Class 12 Sample Paper for 2020 Boards

CBSE Class 12 Sample Paper for 2019 Boards →
Class 12
Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Question 26 - CBSE Class 12 Sample Paper for 2020 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Last updated at Dec. 16, 2024 by

A speaks truth in 80% cases and B speaks truth in 90% cases. In what percentage of cases are they likely to agree with each other in stating the same fact?

A speaks truth in 80% cases and B speaks truth in 90% cases. In what

Question 26 - CBSE Class 12 Sample Paper for 2020 Boards - Part 2

Go Ad-free

Transcript

Question 26 A speaks truth in 80% cases and B speaks truth in 90% cases. In what percentage of cases are they likely to agree with each other in stating the same fact? Given P(A speaks truth) = 80% = 80/100 = 8/10 P(B speaks truth) = 90% = 90/100 = 9/10 Now, P( both agree) = P(both speak truth) + P(both speak false) = P(A speaks truth) × P(B speaks truth) + P(A speaks false) × P(B speaks false) = 8/10 × 9/10 + (1−8/10)×(1−9/10) = 8/10 × 9/10 + (2/10)×(1/10) = 72/100 + 2/100 = 74/100 ∴ Percentage of cases where they agree is 74%

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 14 years. He provides courses for Maths, Science and Computer Science at Teachoo