Question

The digits of F are all the same.
The sum of all the digits of F is 12.
The answer when any two of the digits are multiplied together is also 9.
F is a four-digit number.

How do I figure this out

Answer 1

Well, you know that all of the digits are the same. And you know that the sum of the digits is 12. What does that imply about the value of those digits?

Answer 2

And that there are 4 of those digits

Answer 3

ok

Answer 4

so the numbers are all 3

Answer 5

thank you for your help

Answer 6

Yes, let's check:

3+3+3+3 = 12 "all the digits are the same, and add to 12"
3*3 = 9 "any two digits multiply to 9"
3333 "4-digit number, all digits the same"

all conditions are satisfied, must be a winner!