SOLUTION: There are 3 times more boys than girls in a math class. The average score of the boys on a science test is 90, and the average score of the girls on the same test is 86. What is t

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Question 1144972: There are 3 times more boys than girls in a math class. The average score of the boys on a science test is 90, and the average score of the girls on the same test is 86. What is the average score of the whole class on this test?
A)88
B)86.5
C)87
D)89
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


None of the answer choices is right for the problem as written.

"3 times more boys than girls" --> if the number of girls is x, then the number of boys is 3 times MORE THAN that, which is x+3x = 4x.

Then the class average is

%28x%2886%29%2B4x%2890%29%29%2F%285x%29+=+89.2

Unfortunately, in everyday sloppy English, "3 times more than x" and "3 times as much as x" are used to mean the same thing. But they are different. 3 times as much as x is simply 3x; 3 times MORE THAN x is x, plus x 3 more times: x+3x = 4x.

Apparently the intended wording of the problem is that there are 3 times AS MANY boys as girls. That makes the number of boys 3x if the number of girls is x. Then the class average is

%28x%2886%29%2B3x%2890%29%29%2F%284x%29+=+89 --> answer D