Find the sum of all even numbers between 10 and 20 inclusive.

Step-by-step solution

1. List the even numbers: 10, 12, 14, 16, 18, 20.
2. Add them pairwise: $10+20=30$, $12+18=30$, $14+16=30$.
3. Add the three sums: $30+30+30=90$.
4. Thus the sum is 90.

Concept tested: Summation of even numbers

Published 16 October 2026 · How this solution was prepared and checked