Question

In a two-digit number, the units digit is 5 more than the tens digit. The number itself is three times the sum of its digits. What is this number?

Answer 1

The number is 27.

Explanation:

Since the units digit has to be 5 more than the tens digit, there are only four possible two-digit numbers which satisfy this condition. They are 16, 27, 38, and 49.

Next, the digits can be added and multiplied by three to check that the answer is the same two-digit number.

3 (1 + 6) = 21 does not work because 16 isn't the same as 21.

3 (2 + 7) = 27 does work because 3 * 9 is 27.

3 (3 + 8) = 33

3 (4 + 9) = 39