Question

Find the sum of the series $3+7+11+15+19+....$ up to $10$ terms

• A. $210$
• B. $201$
• C. $120$
• D. $102$

Answer 1

The correct option is A $210$

Given series is $3+7+11+15+19+....$

The Series is in AP

The first term of series is $a=3$

The common difference is $7-3=4$

No of terms is $n=10$

The Sum of terms is $\frac{n}{2}[2a+(n-1\left)d\right]$

$⟹\frac{10}{2}\left[2\right(3)+(10-1\left)4\right]$

$⟹5\times (6+36)$

$⟹210$