SOLUTION: I need to find out how old someone will be when they are 3 times older than someone else for example my mom who is 70 and my niece who is 10 , when will mom be 3 times older than

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Question 921595: I need to find out how old someone will be when they are 3 times older than someone else for example my mom who is 70 and my niece who is 10 , when will mom be 3 times older than my niece.?
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
You need a variable that will be a measure of the time when your mother will be 3 times older than your niece.
If n years from now your mom is 3 times your niece's age, at that time
your mom will be 70%2Bn years old;
your niece will be 10%2Bn years old,
and their ages will be related by
3%2810%2Bn%29=70%2Bn .
That is your equation.

3%2810%2Bn%29=70%2Bn--->3%2A10%2B3n=70%2Bn--->30%2B3n=70%2Bn--->30%2B3n%2B30-n=70%2Bn-30-n--->3n-n=70-30--->2n=40--->n=40%2F2--->n=20
Your mother will be 3 times older than your niece 20 years from now.
At that point, your mother will be 70%2B20=90 ,
and your niece will be 10%2B20=30 .