Question

X and Y are two mutually exclusive events. P(X)= 0.55 and P(X or Y)=0.7. Work out P(not Y) (2 marks)

Answer 1

P(x) = 0.55

P(x ∪ y) = 0.70 →→ P(x) +P(y) = 0.70 →→ 0.55 + P(y) =0.70→→P(y) = 0.15
If P(NOT y) = 1- 0.15 = 0.85