The probabilities are given as,
2P( A )=P( B )= 5 13 and P( A|B )= 2 5 .
As 2P( A )= 5 13 , so, P( A )= 5 26 .
The probability P( A∩B ) is calculated as,
P( A∩B )=P( B )⋅P( A|B ) = 5 13 ( 2 5 ) = 2 13
The probability P( A∪B ) is calculated as,
P( A∪B )=P( A )+P( B )−P( A∩B ) = 5 26 + 5 13 − 2 13 = 5+10−4 26 = 11 26
Therefore, the value of P( A∪B )is 11 26 .