### The average age of a family with 5 members is 28. If one of the 5 members of age 20 is excluded the average age of the family becomes.

A. 25 B. 20 C. 30 D. 24 Answer: Option C
$\begin{array}{l}\text{Total age of 5 members}\\ =\text{5 × 28 = 140}\\ \text{Required average}\\ \begin{array}{l}=\Large\frac{140-20}{4}\\ =\Large\frac{120^{ }}{4}\\ =30\text{ years }\end{array}\end{array}$