# What is the sum of the terms of the series 4+7+10+.....+22?

The sum is $91$

#### Explanation:

It is the sum of an arithmetic progression (series) with first term

${a}_{1} = 4$ and ratio $r = 3$

The sum is

${S}_{7} = \frac{7}{2} \cdot \left({a}_{1} + {a}_{7}\right) = \frac{7}{2} \cdot \left(4 + 22\right) = 7 \cdot 13 = 91$