There are m boys and 12 girls in a class. What is the probability of selecting at random a girl from the class?
- \(\frac{m}{12}\)
- \(\frac{12}{m}\)
-
\(\frac{12}{m+12}\)
- \(\frac{12}{m-12}\)
The correct answer is: C
Explanation
Prob. (a girl) \(=\frac{Number\hspace{1mm} of\hspace{1mm} girls}{Number \hspace{1mm} of \hspace{1mm} boys \hspace{1mm} and \hspace{1mm} girls\hspace{1mm} in \hspace{1mm} class}\\= \frac{12}{m+12}\)