Question

The number 2 is the first even counting number, 4 is the second even number, 6 is the third even number, and so forth. What is the sum of the first twenty-five even counting numbers?

Answer 1

650

Explanation:

The sum of the first n even counting numbers can be found using the formula:

S = n(n+1)

where n is the number of even counting numbers to be added. Since we want to find the sum of the first 25 even counting numbers, n = 25.

Substituting n = 25 into the formula, we get:

S = 25(25+1) = 25(26) = 650

Therefore, the sum of the first 25 even counting numbers is 650.