A speaks truth in 75% cases and B speaks truth in 80% cases. The probability that they contradicts each other in a statement is : |
$\frac{7}{20}$ $\frac{13}{20}$ $\frac{3}{5}$ $\frac{2}{5}$ |
$\frac{7}{20}$ |
The correct answer is Option (1) → $\frac{7}{20}$ Probability of A to speaks the truth = $P(A_T)=0.75$ Probability of A to speaks the lie = $P(A_F)=0.25$ Probability of B to speaks the truth = $P(B_T)=0.80$ Probability of B to speaks the lie = $P(B_F)=0.20$ A speaks truth while B lies = $P(A_T)×P(B_F)$ $=0.75×0.20=0.15$ A lies while B speaks truth = $P(A_F)×P(B_T)$ $=0.25×0.80=0.20$ P (contradiction) = 0.20 + 0.15 = 0.35 |