## Thinking Mathematically (6th Edition)

$\frac{1}{22}$
$\frac{1}{2}$, $\frac{1}{6}$, $\frac{1}{10}$, $\frac{1}{14}$, $\frac{1}{18}$ Every next fraction is increased by $\frac{1}{4}$ in previous fraction So $\frac{1}{18}$ + $\frac{1}{4}$ = $\frac{1}{22}$