Question

Find the missing terms in the arithmetic sequence __,__, 5,8,11,__,__,20.

Answer 1

Given 5,8,11 are 3 consecutive terms

$\Rightarrow 11-8=8=8-5=3$ is the common difference

To get the terms prior to 5, subtract 3

i.e., 5-3=2 & 2-3 = -1

To get the terms after 11, add 3

i.e., 11+3 =14 & 14+3 =17