Question

On the first day of class, Willem’s Algebra I teacher agreed to assign no homework for a week to the first student to answer this question: There is a positive two-digit integer that is divisible by the sum of its digits and has exactly five factors. What is the sum of its factors? (This is for my little sister in middle school)

Answer 1

Answer:

81

Step-by-step explanation:

There are only two numbers with 5 factors that are only two digits. 16 and 81 are the only options and when you add 8+1=9 and 81 is divisible by 9.

Have fun with no homework for a week!