SOLUTION: A girl went to school (or college) and the teacher asked her how old she was. She told the teacher she didn't know. But, she does know that she is half her mother's age. The teache

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: A girl went to school (or college) and the teacher asked her how old she was. She told the teacher she didn't know. But, she does know that she is half her mother's age. The teache      Log On

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Question 961884: A girl went to school (or college) and the teacher asked her how old she was. She told the teacher she didn't know. But, she does know that she is half her mother's age. The teacher then asked her how old her mother is. Once again, the girl said she did not know, but she does know that her dad is 5 years older than her mother. So the teacher asked her how old her dad was - once again the girl said she didn't know. The girl told the teacher that she does know that if you add the 3 ages together you will get 100 .
How old is the girl?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = the girl's age
+2x+ = her mother's age
+2x+%2B+5+ = her father's age
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+x+%2B+2x+%2B+2x+%2B+5+=+100+
+5x+%2B+5+=+100+
+5x+=+95+
+x+=+19+
The girl is 19