SOLUTION: The mean age of a group of eight girls was 15. One more girl joins the group and the mean age became 14. How old is the ninth girl?
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Question 1003790: The mean age of a group of eight girls was 15. One more girl joins the group and the mean age became 14. How old is the ninth girl?
Answer by harpazo(655) (Show Source): You can put this solution on YOUR website!
14X9-15X8 = 126-120 = 6 years
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