Question

Find the sum of fterms of AP whose first term is 26 and last term is 14.

• A. 200
• B. 250
• C. 300
• D. 400

Answer 1

The correct option is D 400

The sum of first n terms of arithmetic series formula can be written as,

$S_n=\frac{n}{2}$[First term + Last term] ... eq ( 1 )

n = number of terms = 20

First term = 26

Last term = 14

$\therefore S_n=\frac{20}{2}[26+14]=400$ (Ans $\to$ D)