Whats the digit?

Question

Find a 2 digit number where 3 times the sum of its digits is equal to 18. The tens digit of the number is half of it ones digit.

Answer 1

This is how I approached the problem:

 

We need two digits (lets call them x & y) that have 3*(x+y) = 18.

 

The 10's digit is half of the 1's digit.

 

So we have a few options:

1 & 2, 2 & 4, 3 & 6, and 4 & 8

 

We want: 3(x + y) = 18

 

Lets solve for x + y, by dividing both sides by 3:

x + y = 6

 

So the two numbers must add up to 6. Therefore we want the numbers 2 & 4.

 

Thus, our answer is 24!