Question 16
MediumOriginal questionThe average of eight numbers is 25. Each number is multiplied by 3 and then 4 is subtracted from it. What is the new average?
Show the answer and explanation
CorrectNot quiteAnswer B
Correct answer: B
Explanation
Multiplying every value by 3 multiplies the average by 3: 75.
Subtracting 4 from every value subtracts 4 from the average: .
Worth noting
The average follows the same operation as the values. 79 adds the 4 instead of subtracting it.
- Concept
- Effect of multiplying and shifting every value on the average
- Typical timeTypical
- 40 s
- Your timeYours
- —
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Ten questions from Averages, at your own pace.