Problema Solution
The sum of Rob and his son's age is 108. Eighteen years ago, Rob was three times as old as his son. How old are they now?
Answer provided by our tutors
let
r = the age of Rob now
s = the age of Rob's son now
The sum of Rob and his son's age is 108
r + s = 108
Eighteen years ago, Rob was three times as old as his son
r - 8 = 3(s - 8)
by solving the system of equations
r + s = 108
r - 8 = 3(s - 8)
we find
r = 77 years
s = 31 years
click here to see the step by step solution of the system of equations
Rob is 77 years old now.
Rob's son is 31 years old now.