SOLUTION: First question : A total of 50 juniors ande seniors were given a mathematics test. The 35 juniors attained an average score of 80while th 15 seniors attained an average of70. Wh

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Question 317490: First question :
A total of 50 juniors ande seniors were given a mathematics test. The 35 juniors
attained an average score of 80while th 15 seniors attained an average of70.
What the average score for all 50 students who took the test?
A. 73
B. 75
C. 76
D. 77
E. 78

SECOND question :
Adam tried to compute the average of his 7 test scores. He mistakenly divided
the correct sum of all of his test scores by 6 , which yielded 84.
What is Adam's correct average test score?
A. 70
B. 72
C. 76
D. 77
E. 98
Found 2 solutions by Edwin McCravy, stanbon:
Answer by Edwin McCravy(20065)   (Show Source): You can put this solution on YOUR website!
First question :
A total of 50 juniors ande seniors were given a mathematics test. The 35 juniors
attained an average score of 80while th 15 seniors attained an average of70.
What the average score for all 50 students who took the test?

 where A = Average, S = Sum of scores, N = number

Multiply through by N

>>...The 35 juniors attained an average score of 80...<<

Substitute 80 for A and 35 for N





So the sum of the scores of the juniors was 2800

>>...the 15 seniors attained an average of 70...<<



Substitute 70 for A and 15 for N





So the sum of the scores of the seniors was 1050

So the sum of the scores of all 50 was 2800 + 1050, or 3850

>>...What the average score for all 50 students who took the test?...<<



Substitute 3850 for S and 50 for N

SECOND question :
Adam tried to compute the average of his 7 test scores. He mistakenly divided
the correct sum of all of his test scores by 6 , which yielded 84.
What is Adam's correct average test score?



Substitute 84 for A, and 6 for N (which should have been 7





Now we do it correctly. Substitute 504 for S and 7 for N







Edwin
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
A total of 50 juniors ande seniors were given a mathematics test. The 35 juniors
attained an average score of 80while th 15 seniors attained an average of70.
What the average score for all 50 students who took the test?
-------------
Total Junior points: 35*80 = 2800
Total Senior points: 15*70 = 1050
====
Average of total = (2800+1050)/(35+15) = 77
========
A. 73
B. 75
C. 76
D. 77
E. 78
=========================================================
SECOND question :
Adam tried to compute the average of his 7 test scores. He mistakenly divided
the correct sum of all of his test scores by 6 , which yielded 84.
What is Adam's correct average test score?
---
Equation:
(correct sum)/6 = 84
correct sum = 6*84 = 504 points
----
corrected average test score = 504/7 = 72
=================================================
A. 70
B. 72
C. 76
D. 77
E. 98
------------------------------
Cheers,
Stan H.
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