Question

Look at the table. Make a conjecture about the sum of the first 25 positive even numbers.

The sum is 24 × 24.
The sum is 25 × 25.
The sum is 24 × 25.
The sum is 25 × 26.

Answer 1

first 3 sums = 3*4
first 4 sums = 4*5
first 5 sums = 5*6

Answer 2

first 18 sums = 18*19