Which composite number can divide the sum of the first 12 natural numbers?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 6.
A composite number is a number that has more than two factors (1 and itself).
Sum of the first n natural numbers = [n(n+1)]/2
Sum of the first 12 natural numbers = [12(12 + 1)/2 = (12 × 13)/2 = 156/2 = 78
The factors of 78 = 1, 2, 3, 6, 13, 26, 39, and 78
The composite factors = 6, 26, 39, and 78
In the given option, the number 6 is available.
Therefore, the required number is 6.