SOLUTION: In a science test, a class of 30 students had an average of 80. The 20 girls in the class had an average of 85. What is the average of the 10 boys in the class?
A) 60
B) 70
C
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A) 60
B) 70
C
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Question 721137: In a science test, a class of 30 students had an average of 80. The 20 girls in the class had an average of 85. What is the average of the 10 boys in the class?
A) 60
B) 70
C) 80
D) 85
E) 90 Answer by KMST(5328) (Show Source):
You can put this solution on YOUR website! For scores
For the girls the sum of the scores was and -->
For the class, the sum of the scores is ,
and the average is = -->
Since is the sum of the boys' scores, ,
plus the sum of the girls' scores --> -->
The average for the boys is the sum of their scores divided by the number of boys:
