SOLUTION: Jack is twice as old as Jill, but in five years time he will only be one and a half times as old. How old are Jack and Jill now?

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Question 1152323: Jack is twice as old as Jill, but in five years time he will only be one and a half times as old. How old are Jack and Jill now?
Found 2 solutions by MathLover1, MathTherapy:
Answer by MathLover1(20850)   (Show Source): You can put this solution on YOUR website!

let Jack's age be and Jill's age
if Jack is twice as old as Jill, we have
........eq.1
if in five years time he will only be and a times as old, we have



........eq.2
from eq.1 and eq.2 we have





go to eq.1
........eq.1, substitute


Jack is years old now and Jill is years old now


Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!

Jack is twice as old as Jill, but in five years time he will only be one and a half times as old. How old are Jack and Jill now?
You don't have to make this a COMPLEX solution by creating 2 separate variables. So, proceed as follows:

Let Jill's age be J

Then Jack's is 2J

We then get: 2J + 5 = 1.5(J + 5)

2J + 5 = 1.5J + 7.5

2J - 1.5J = 7.5 - 5

.5J = 2.5

Jill's age, or 

You should now be able to find Jack's age! 

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