If a person A speaks the truth in 80% cases and the person B speaks the truth in 75% cases, then the probability that they contradict each other in a statement is
If a person A speaks the truth in 80% cases and the person B speaks the truth in 75% cases, then the probability that they contradict each other in a statement is
Solution
Person A speaks the truth in 80% of cases, so A speaks the truth with probability and lies with probability .
Person B speaks the truth in 75% of cases, so B speaks the truth with probability and lies with probability .
Two people contradict each other when one tells the truth and the other lies.
A tells the truth and B lies:
Probability
A lies and B tells the truth:
Probability
Total probability of contradiction:
Therefore, the probability that they contradict each other is .
Related questions:
2025: 13 May Shift 1
2023: 15 June Shift 2
2026: 29 May Shift 2