(i)
The given probabilities are,
P( A )= 1 3 P( B )= 1 5 P( A∩B )= 1 15
We know that,
P( A∪B )=P( A )+P( B )−P( A∩B )
Substitute values of P( A ), P( B ) and P( A∩B ) in above formula.
P( A∪B )= 1 3 + 1 5 − 1 15 = 5+3−1 15 = 7 15
Thus, the value of P( A∪B ) is 1 15 .
(ii)
The given probabilities are,
P( A )=0.35 P( A∩B )=0.25 P( A∪B )=0.6
We know that,
P( A∪B )=P( A )+P( B )−P( A∩B )
Substitute values of P( A ), P( A∪B ) and P( A∩B ) in above formula.
0.6=0.35+P( B )+0.25 P( B )=0.6+0.25−0.35 =0.5
Thus, the value of P( B ) is 0.5.
(iii)
The given probabilities are,
P( A )=0.5 P( B )=0.35 P( A∪B )=0.7
We know that,
P( A∪B )=P( A )+P( B )−P( A∩B )
Substitute values of P( A ), P( B ) and P( A∪B ) in above formula.
0.7=0.5+0.35 P( A∩B )=0.5+0.35−0.7 =0.15
Thus, the value of P( A∩B ) is 0.15.