#### Answer

a)0.0741
b)0.8.
c)Inverse not correct. Many patients will have to undergo unnecessary treatments.

#### Work Step by Step

a)We know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$, hence $P(Malignant|Positive)=\frac{8}{8+100}=0.0741.$
b)We know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$, hence $P(Positive|Malignant)=\frac{8}{8+2}=0.8.$
c) 75% is much more than 0.0741=7.41%, hence the inverse is not correct. Hence many patients will have to undergo unnecessary treatments.