Question

Answer the following
The first term of an AP is -7 and the common difference 5, Find its ${18}^{th}$ term.

Answer 1

We have,

$a=-7,d=5,n=18$

We know that $n$th term of A.P.

$=a+(n-1)d$

Therefore,

$=-7+(18-1)5$

$=-7+17\times 5$

$=-7+85$

$=78$

Hence, this is the answer.