The factors of 55 are: 1, 5, 11, 55.
\[ 1 + 5 + 11 + 55 = 72 \]
Thus, the correct answer is 72 (Option D).
Arun’s present age in years is 40% of Barun’s. In another few years, Arun’s age will be half of Barun’s. By what percentage will Barun’s age increase during this period?