Question

A man is thrice as old as his son.Five years ago the man was four times as old as his son.Find their present ages.

Answer 1

Let mans age be x
Let sons age be y

x=3y
x-3y=0__________(1)

Five years ago
x-5=4(y-5)
x-5=4y-20
x-4y=-15________(2)

(2)-(1)
-y=-15
y=15
therefore x=3×15=45

x=45 , y=15