Family members

Three years ago, the average age of a family of five members was 27 years. The present average age is also 27 year after the inclusion of a child into the family. Find the age of the child .

Correct answer:

x =  12

Step-by-step explanation:

$$\begin{gathered} 27=\frac{5\cdot (27+3)+x}{5+1} \\ 27\cdot 6=5\cdot (27+3)+x \\ x=12 \\ x=\frac{12}{1}=12 \\ x=12 \end{gathered}$$

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