Question

Mr. Anders was three times as old as Kate 5 years ago. Their total age now is 42 years. How old is Kate now?

Answer 1

We can write this as two equations. Call Mr. Anders' age A and Kate's age K:

`A-5=3(K-5)`

`A+K=42`

Then solve for A in the second equation:

`A=42-K`

Substitute this into the first equation:

`(42-K)-5=3(K-5)`

`-K+37=3K-15`

`52=4K`

`K=13`