### What is the sum of the first 17 terms of an arithmetic progression if the first term is -20 and last term is 28?

A. 68 B. 156 C. 142 D. 242 Answer: Option A

### Solution(By Apex Team)

First term of AP = a = -20 and last term = l = 28 Number of terms = n = 17 \begin{aligned}&\text{ Sum of }\mathrm{AP}=\frac{\mathrm{n}}{2}(\mathrm{a}+\mathrm{l})\\ &=\frac{17}{2}(-20+28)\\ &=17\times4\\ &=68\end{aligned}

A. 22
B. 25
C. 23
D. 24

A. 5
B. 6
C. 4
D. 3

A. -45
B. -55
C. -50
D. 0