Problem of the Week: What Number Am I?

May 3, 2020 | Folsom










Did you figure it out? Let's look at the solution!


The second smallest prime number is 3, so the ones digit is 3.

The tens digit is twice as large as the hundreds digit. This means our hundreds digit cannot be greater than or equal to 5 since those numbers doubled are two-digit numbers. That means our possible numbers are 123, 243, 363, and 483.

Of these choices, 243 is the only number divisible by 9 since 2 + 4 + 3 = 9 and 9 is divisible by 9. 


Look forward to next week's problem!