Question

Harry intends to complete a BSc degree. He has to take either Mathematics A or Physics A in his first year. If he takes Mathematics A, he can take chemistry A or Mathematics B in His second year. If he takes Physics A, he has to take Mathematics A in his second year. When Harry has to make a choice between two subjects both are likely to be chosen

Answer 1

a) Draw a decision tree

b)

$$P(MathA)=\frac{1}{2}$$

(c)

$$P(MathA\ and\ MathB)=\dfrac{1}{2}(\dfrac{1}{2})=\dfrac{1}{4}$$