Question

Kevin is 3 times as old as Daniel. 4years ago, Kevin was 5 times as old as Daniel.How old is Daniel now?

Answer 1

Let
`k=` Kevin's age
Let
`d=` Daniel's age

We know

`k=3d`
and

`k-4=5(d-4)`

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

`3d-4=5(d-4)`

`\rightarrow3d-4=5d-20`

`\rightarrow-2d-4=-20`

`\rightarrow-2d=-16`

`\rightarrow d=8`

So Daniel is 8 years old.