Probability Part 1

The probability of speaking truth by A,P(A)=‌

4

5

. The probability of not speaking truth by A,P(A)=1−‌

4

5

=‌

1

5

.
The probability of speaking truth by B,P(B)=‌

3

4

. The probability of not speaking truth of B,P(B)=‌

1

4

.
The probability that they contradict each other
=P(A)×P(B)+P(A)×P(B)
=‌

4

5

×‌

1

4

+‌

1

5

×‌

3

4

=‌

1

5

+‌

3

20

=‌

7

20