The sum 1² + 2² + 3² + ... + n² is:

1. A n(n+1)(2n+1)/6 Correct answer
2. B n(n+1)²/4
3. C n²(n+1)/2
4. D n(n+1)/2

Solution

Sum of squares: 1²+2²+...+n² = n(n+1)(2n+1)/6.

About this question

Subject: Mathematics · Chapter: Sequences and Series · Topic: Special Series

This question is part of PrepWiser's free JEE Main question bank. 16 more solved questions on Sequences and Series are available — start with the harder ones if your accuracy is >70%.

More Sequences and Series questions

• Easy TRUE_FALSE

  The sum of first n odd numbers is n².

• Easy INTEGER

  The sum of cubes of first n natural numbers is $x$.

• Easy MCQ

  The sum 1 + 2 + 3 + ... + n is:

• Easy TRUE_FALSE

  If a, b, c are in HP, then a, b, c are also in GP.

• Easy INTEGER

  The harmonic mean of 2 and 4 is $x$.