Question

Robert's father is 4 times as old as
Robert. After 5 years, father will be
three times as old as Robert. Find
their present ages.

a. 5,20
b. 6,24
c. 20,80
d. 10,40​

Answer 1

Robert's age = x | Robert's father's age = 4x

After 5 years, Robert's age = (x + 5)

After 5 years, Robert's father's age = 3(x + 5) = 3x + 15

We need to solve for x

4x + 5 = 3x + 15

4x - 3x = 15 - 5

x = 10

Robert's age = 10 years old

Robert's father's age = 10(4) = 40 years old