Question

The sum of the first 55 terms of an A.P. is 3300. Find the ${28}^{th}$ term.

• A. 55
• B. 60
• C. 65
• D. 70

Answer 1

The correct option is B 60

Let $a$ and $d$ be the first term and common difference of the given AP respectively.
Given, $S_{55}=3300$
$\Rightarrow \frac{55}{2}[2a+(55-1\left)d\right]=3300$

$\Rightarrow 55[a+27d]=3300$
$\Rightarrow a+27d=60$
Hence, ${28}^{th}$ term $a_{28}=a+27d=60$