Question

A number between 10 and 100 is four times the sum of its digits. If the product of two digits is 8, find the sum of digits of the number.​

Answer 1

24 is the number. The sum of its digits is 6.

Explanation:

There are four two-digit numbers the product of whose digits is 8: 18, 24, 42, and 81. Of these numbers, 24 is four times the sum of its digits:

24 = 4 × 6 = 4 × (2 + 4)