A total of 50 juniors and seniors were given a mathematics test. The 35 juniors attained an average score of 80 while the 15 seniors attained an average of 70. What was the average score for all 50 students who took the test?
A. 73
B. 75
C. 76
D. 77
E. 78
2007-12-05 14:18:44 · 6 answers · asked by Astro J 1 in Science & Mathematics ➔ Mathematics
total score for the juniors =35x80=2800
total score for the seniors =15x70=1050
Total score of the whole group =3850
Total members=50
The grand average=3850/50=77
So the answer is "D"
2007-12-05 14:29:50 · answer #1 · answered by vcs7578 5 · 0⤊ 0⤋
D. 77
If 35 got 80 and 15 got 70 (when finding the average of multiple averages you can say that all examples have the value of the average, like an average of 70 means those 15 people all got 70 if working with more than one average) so:
(35x80+15x70)/50=77
2007-12-05 22:28:29 · answer #2 · answered by hillhavengirl 1 · 0⤊ 0⤋
( (35 * 80) + (15 * 70)) / 50 = 77
2007-12-05 22:24:42 · answer #3 · answered by MasterGoofy 2 · 0⤊ 0⤋
B.75 What you do is you take 70 and 80 and add them together. Then divide them by 2. Then theres your answer ((:
2007-12-05 22:21:59 · answer #4 · answered by shortyx3 2 · 0⤊ 0⤋
35 * 80 = 2,800
15 * 70 = 1,050
2,800 + 1.050 = 3,850
3,850/50 = 77
D.
2007-12-05 22:22:36 · answer #5 · answered by Steve B 6 · 0⤊ 0⤋
35x80=2800
15x70=1050
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50 students scored totalled together = 3850
divide 3850 by 50 = 77%
so its D
2007-12-05 22:30:06 · answer #6 · answered by mark s 1 · 0⤊ 0⤋