Question

Mr. Jacobs is 4 times as old as his son. Five years ago, he was was 9 times as old as his son. What is Mr. Jacob's age?

Answer 1

Mr Jacobs is `32`.

Explanation:

Let:

• `"Mr Jacobs' age" = J`

• `"Mr Jacobs' son's age" = S`

`J = 4S`
`J - 5 = 9(S - 5) = 9S - 45`

`:. J = 4S = 9S - 40`
`" " 5S = 40`
`" " S = 8`

`J = 4(8)`
`J = 32`

`32 - 5 = 9(8 - 5)`
`27 = 9 * 3 " is TRUE"`