A person $P$ speaks truth in $75 \%$ cases and another person $R$ in $80 \%$ cases. Then, the probability…
A person $P$ speaks truth in $75 \%$ cases and another person $R$ in $80 \%$ cases. Then, the probability that they likely to contradict each other in narrating the same event is
$\frac{7}{20}$
$\frac{7}{10}$
$02$
$0.3$
Solution
' Favourable cases -
Case I $A$ speaks truth, $B$ does not Case II $B$ speaks truth, $A$ does not $\therefore$ Probability $=\frac{3}{4} \times \frac{1}{5}+\frac{1}{4} \times \frac{4}{5}=\frac{7}{20}$