The average of first 138 even numbers is

Correct option is B

Given:

We are asked to find the average of the first 138 even numbers.

Formula Used:
The average of first n even numbers = $$\frac{\text{Sum of first } n \text{ even numbers}}{n} = \frac{n(n + 1)}{n} \times 1 = n + 1$$​

Solution:

Let n = 138 (number of even numbers)

Average = n + 1 = 138 + 1 = 139