Question

If a speaks the truth 60% of the times, b speaks the truth 50% of the times. What is the probability that at least one will tell the truth?

Answer 1

Answer:

4/5 is probability that at least one will tell the truth

Step-by-step explanation:

a speaks the truth 60% of the times

so probability of a speaking truth = 60/100 = 3/5

so probability of a speaking lie = 1 - 3/5 = 2/5

b speaks the truth 50% of the times

so probability of b speaking truth = 50/100 = 1/2

so probability of b speaking Lie = 1 - 1/2 = 1/2

Probability that both a and b will lie ( will not speak truth) = (2/5) * (1/2) = 1/5

probability that at least one will tell the truth = 1 - both will not speak truth

= 1 - 1/5 = 4/5

4/5 is probability that at least one will tell the truth