Multiple choice general knowledge math & puzzles

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9

  1. 51

  2. 45

  3. 55

  4. 50
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the sum of first 9 natural numbers. Use the formula n(n+1)/2 = 9×10/2 = 45. Or verify by adding: 1+9=10, 2+8=10, 3+7=10, 4+6=10, plus 5 = 45.

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