### If the arithmetic mean of 7, 5, 13, x and 9 is 10, then the value of x is :

A. 10 B. 12 C. 14 D. 16
$\begin{array}{l}\text{Arithmetic mean}\\ \Large\frac{\text{ Total sum }}{\text{ Total number }}\\ \text{According to the question,}\\ \Rightarrow10=\frac{7+5+13+x+9}{5}\\ \text{⇒ 50 = x + 34}\\ \text{⇒ x = 50 – 34}\\ \text{⇒ x = 16}\end{array}$