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Haven
Senior Member

USA
28 Posts

 Posted - 04/22/2008 :  11:33:39 The average (arithmetic mean) of the test scores of a class of "p" students is 70, and the average of the test scores of a class of "n" students is 92. When the scores of both classes are combined the aveage is 86. What is the value of p n?There was no answer or explaination given for this problem.I would like a step by step explaination if possible so that I can explain this problem to students I sometimes tutor.Also, it was asked if prime factoring can be used to solve this problem?Thanks for any and all help.Haven Williams

Subhotosh Khan

USA
9117 Posts

 Posted - 04/22/2008 :  12:08:13 quote:Originally posted by HavenThe average (arithmetic mean) of the test scores of a class of "p" students is 70, and the average of the test scores of a class of "n" students is 92. When the scores of both classes are combined the aveage is 86. What is the value of p n?There was no answer or explaination given for this problem.I would like a step by step explaination if possible so that I can explain this problem to students I sometimes tutor.Also, it was asked if prime factoring can be used to solve this problem?Thanks for any and all help.Haven WilliamsThis is not a difficult problem:Start from the definition of average and form the equationp*70 + n*92 = (n+p)*86Now show us where do you go from here.

Haven
Senior Member

USA
28 Posts

 Posted - 04/23/2008 :  10:30:33 I am not sure what you mean? I found the answer and it was 3 8

Subhotosh Khan

USA
9117 Posts

 Posted - 04/23/2008 :  13:43:27 quote:Originally posted by HavenI am not sure what you mean? I found the answer and it was 3 8<<
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