Question

If $n^{th}$ term of an A.P. is $2n+1$, then find its common difference.

Answer 1

Given $n^{th}$term of A.P is $=$ $2n+1$
Thus,$1$st term $=3$ [for $n=1$]
$2$nd term $=5$ [for $n=2$]
Common difference, $d=1$st term$-2$nd term.
$\Rightarrow d=5-3$
$=2$
Therefore, Common difference is $=2$.