SOLUTION: The average of the first 6 scores was 12. The average of the next 12 scores was 36.What was the overall average ?

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Question 473566: The average of the first 6 scores was 12. The average of the next 12 scores was 36.What was the overall average ?
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
Since the average of the first 6 scores was 12, the sum of the 6 scores was 72.
We know that because the average = sum / count.
12 = x / 6
72 = x
x = 72
.
Using the same logic we find that
36 = y / 12
y = 12 * 36
y = 432
.
So, we have 18 scores that sum to 72+432 = 504
Average = 504/18
Average = 28.
.
Done.