Middle School

Ed is 8 years older than his brother John. Five years ago, Ed was 3 times as old as John. Find their present ages

Answer :

To find the present ages of Ed and John, we set up a system of equations where Ed is 8 years older than John and was 3 times John's age five years ago. Solving the equations, we find that John is 9 years old and Ed is 17 years old.

Let's denote John's current age as J and Ed's current age as E. According to the problem, Ed is 8 years older than John, so we can express this as E = J + 8. Five years ago, Ed was 3 times as old as John, which can be written as E - 5 = 3 * (J - 5).

Now we can set up our equations:

  1. E = J + 8
  2. E - 5 = 3 * (J - 5)

We can substitute the first equation into the second to find the value of J:

  1. (J + 8) - 5 = 3 * (J - 5)
  2. J + 3 = 3J - 15
  3. 3 + 15 = 3J - J
  4. 18 = 2J
  5. J = 9

Now that we know John's age is 9, we can find Ed's age by adding 8:

E = J + 8

E = 9 + 8

E = 17

Therefore, John is currently 9 years old, and Ed is currently 17 years old.

Ed is 15, and John is 7.