Problema Solution
The sum of the ages of John and Mary is 32. Four years ago, John was twice as old as Mary. Find the present age of each.
Answer provided by our tutors
Let
x = John's present age
y = Mary's present age
x + y = 32
4 years ago John's age was x - 4 while Mary's age was y - 4.
x - 4 = 2(y - 4)
We have the following system of equations:
x + y = 32
x - 4 = 2(y - 4)
........
click here to see the system of equations solved for x and y
........
x = 20 years
y = 12 years
John's present age is 20 years, while Mary's present age is 12 years.