GATE Civil Engineering (CE) 2020 Shift 1 Solved Paper

As per the given question, the sequence of given AP is, 2 _ _ _ _ _ _ _ 34
In this sequence first term $\left(\mathit{a}\right)=2$
Last term $\left(\mathit{t}\mathit{n}\right)=34$
So, as per the relation,
${\mathit{t}}_{\mathit{n}}=\mathit{a}+\left(\mathit{n}-1\right)\mathit{d}$
$\mathit{n}\to$ number of terms
$\mathit{d}\to$ common difference
$34=2+\left(9-1\right)\mathit{d}$
$\mathit{d}=4$
So, the A.P. becomes, $2,6,10,14,18,22,26,30,34$
Sum of 7 terms between 2234 is 126