Question

Insert $20$ AM. between $2$ and $86.$

Answer 1

Here $2$ is the first term and $86$ is the ${22}^{nd}$ term of A.P. so $86=2+\left(21\right)d$
$\Rightarrow$ $d=4$
so the series is $2,6,10,14,.......,82,86$
$\therefore$ required means are $6,10,14,...,82.$