Question

Is 51 a term of the AP $5,8,11,14,....?$

Answer 1

Here,

$a=5$ and $d=3$

Let 51 be the nth term of the AP.

$a+(n-1)d=51$

$5+3(n-1)=51$

$3n=49$

$n=16\frac{1}{3}$

But, the number of terms cannot be a fraction.

Hence, $51$ is not a term of the given AP.