Chapter 11 - Probability and Statistics - 11-3 Probability of Multiple Events - Practice and Problem-Solving Exercises - Page 692: 24

$0.47 \text{ or } 47\%$

Use the formula $P(S \space or \space T)=$ $P(S)$ $+$ $P(T)$ which is used for mutually exclusive events: $P(S \space or \space T)=$ $P(S)$ $+$ $P(T)$ $P(S \space or \space T)=$ $30$% $+$ $17$% $P(S \space or \space T)=$ $47\%=0.47$