Question 1204000
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You have received two responses showing valid solutions using two variables.<br>
Often the actual algebra required to solve the problem is easier if you can set the problem up using a single variable.  Let's see what happens if we do that.<br>
Let x = Chito's age 10 years ago
Then 3x = Pepito's age 10 years ago<br>
Chito's age 10 years from now will be x+20; Pepito's age then will be 3x+20.  At that time, Pepito's age will be twice Chito's age:<br>
{{{3x+20=2(x+20)}}}
{{{3x+20=2x+40}}}
{{{x=20}}}<br>
10 years ago, Chito's age was x=20 and Pepito's age was 3x=60.<br>
So now their ages are x+10 = 30 and 3x+10 = 70.<br>
ANSWER: the ratio of their ages is 30:70, or 3:7 (or 7:3)<br>