Problema Solution

A year ago Alex was 4 times as old as his sister Cara. This year he is only 3 times as old as Cara. How old were Alex and Cara last year? How old are they this year?

Answer provided by our tutors

let age of alex = x

cara = y

1 year ago:

(x-1) = 4(y-1)

==>x = 4y - 3

now:

x = 3y

==>3y = 4y-3

y=3

x=9

age of alex = 9

age of cara = 3