Question

Ben is 20 years older than Daniel. Ben and Daniel first met two years ago. Three years ago, Ben was 3 times as old as Daniel.How old is Ben now?

Answer 1

Let
`b=` Ben's age
Let
`d=` Daniel's age

We know:

`b=d+20`
and

`b-3=3(d-3)`

Plug the value of
`b` into the second equation:

`(d+20)-3=3(d-3)`

`\rightarrow d+17=3d-9`

`\rightarrow-2d+17=-9`

`\rightarrow-2d=-26`

`\rightarrow d=13`

Since Ben is 20 years older than Daniel, Ben is 13+20=33 years old.