Question

The sum of ten consecutive natural numbers is $180$ more than the average of the numbers. What is the sum of the largest and the smallest of the ten numbers?

• A. $45$
• B. $48$
• C. $50$
• D. $40$

Answer 1

The correct option is D $40$

Let the sum of the first and the last number be x.
As the average of n consecutive numbers is equal to average of first and last number.
According to the question.
$\Rightarrow 5x=\frac{x}{2}+180\Rightarrow x=\frac{180\times 2}{9}=40$
Therefore, the sum of the first and the last number is $40$.