The chance that a software engineer will debug an error X correctly is 80%. The chance that software with the error X will crash after the correct debugging is 30%. The chance of crash of the software by wrong debugging is 70%. A software with the error X crashed. The probability that its error was debugged correctly is:

Question

Question

This question was previously asked in

SSC CGL Tier-II ( JSO ) 2019 Official Paper ( Held On : 17 Nov 2020 )

Answer 1

Given

P(A I B) = 30% = 0.3

P(A) = 80% = 0.8

P(B I A’) = 70% = 0.7

P(A’) = 100% - 80% = 2-0% = 0.2

Formula

P(A I B) = P(A I B). P(A)/P(B) = [P(A I B). P(A)]/[P(A I B). P(A) + P(B I A’) P(A’)]

Calculation

P(A I B) = (0.3 × 0.8)/(0.3 × 0.8 + 0.7 + 0.2)

⇒ 0.24/(0.24 + 0.14)

⇒ 0.24/0.38

∴ The probability that its error was debugged correctly is 12/19