Problema Solution
The average of the first 3 weights was 20 pounds. The average of the next 12 weights was 25 pounds. What was the overall average of the weights?
Answer provided by our tutors
If the average of the first 3 is 20, then the sum of the first 3 is 60.
Likewise, the sum of the next 12 is 12(25) = 300.
This means that the sum of the first 15 is 300 + 60 = 360, thus their average is 360 / 15 = 24.