Question

'X' speaks truth in 60% and 'Y' in 50 % of the cases. The

probability that they contradict each other narrating the same

incident is -

• A. $\frac { 1 } { 4 }$
• B. $\frac { 1 } { 3 }$
• C. $\frac { 1 } { 2 }$
• D. $\frac { 2 } { 3 }$

Answer 1

Answer: (C)

$\frac { 1 } { 2 }$

Answer 2

P(x) . P( $\overline { \mathrm { y } }$ ) + P( $\overline { \mathrm { X } }$ ) . P(y)

= $\frac { 60 } { 100 }$ × $\frac { 50 } { 100 }$+ $\frac { 40 } { 100 }$ × $\frac { 50 } { 100 }$= $\frac { 1 } { 2 }$