# Suppose S and T are mutually exclusive events. Find P(S or T) if P(S) = 8/9 and P(T) =1/10?

## 4/45 89/19 89/90 9/19

Hence$P \left(S \mathmr{and} T\right) = P \left(S\right) + P \left(T\right) = \frac{8}{9} + \frac{1}{10} = \frac{80}{90} + \frac{9}{90} = \frac{89}{90}$.