Question

Kevin is 39 years old and Daniel is 3 years old How many years will i take until Kevin is only 4 times as old as Daniel?

Answer 1

`9` years

Explanation:

Let `y` be the required number of years.

Then after `y` years
`color(white)("XXX")39+y = 4 xx( 3+y)`

`color(white)("XXX")39+y = 12 +4y`

`color(white)("XXX")27=3y`

`color(white)("XXX")9=y`