Question 1012028:  maria is now 3 years older than her sister, Ann. Four years ago, Maria's age was one-half Anna's age.How old is each girl now? 
 Answer by ValorousDawn(53)      (Show Source): 
You can  put this solution on YOUR website! Let Maria's age be m, Ann's age be a.
 
Maria is now 3 years older than her sister, Ann. This gives us m=a+3.
 
 
Four years ago, Maria's age was one-half Anna's age. This gives us (m-4)/2=a-4. Divided by two for the one half part. Both m and a have 4 subtracted because both ages are from 4 years ago.
 
 
We can invoke substitution for this problem. Since m=a+3, we get a+3-4/2=a-4. 
a-1=2a-8 
a=7
 
If Ann's age is 7, and Maria is three years older, then Maria must be 10. 
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