Which one of the following is a factor of the sum of first twenty-five natural numbers ?
Which one of the following is a factor of the sum of first twenty-five natural numbers ? Correct Answer 13
Sum first n natural numbers$${\text{ = }}\left = 25 \times 13$$
Sum of first 25 natural numbers
$${\text{ = }}\frac{{25(26)}}{2} = 25 \times 13$$
Now check option
Clearly, we can see 13 is factor
So, '13' is answer