Question

If a tells truth 4 out of 5 times and b tells the truth 3 out of 4 times , what is the probability that both expressing the same fact contradict each other?

Answer 1

A tells truth 4/5 times
B tells it 3/4 times
Take the lcm of 4 and 5
=20
4/5 = 16/20
3/4= 15/20
A lies 4/20 times
B lies 5/20 times
So, a speaks truth 1 more time and that time the other will lie so 1/20 times they will contradict each other
Hope it helps