1² + 2² + 3² + … + 25²= ?
Show answer & explanation
Correct answer: B
Explanation
Given:
1² + 2² + 3² + … + 25²
According to the formula:
1² + 2² + … + n² = n(n + 1)(2n + 1) / 6
n = 25
= 25 × 26 × 51 / 6
= 25 × 26 × 51 ÷ 6
= 25 × 13 × 51 ÷ 3
= 25 × 13 × 17
= 25 × 221
= 5525