Multiple choice general knowledge math & puzzles 1^2+2^2+3^2=? n(n+1)/2 n(n+1)(2n+1)/6 [n(n+1)]^2 all of the above Reveal answer Fill a bubble to check yourself B Correct answer Explanation The formula for the sum of the squares of the first n natural numbers (1^2 + 2^2 + ... + n^2) is given by n(n+1)(2n+1)/6. The other options represent the sum of n numbers or the sum of cubes.