Pedro will lose 11 pencils.
What is an average?
Calculating the outcome of multiplying the total of numerous quantities by the number of quantities, then dividing this result.
Here, we have
Pedro has twelve more pencils than Peter.
Peter has nine more pencils than Paul
Then,
The three quantities of pencils are x, x - 12, and x - 21.
The average of this is (x - 33)/3 = x - 11.
Hence, Pedro will lose 11 pencils.
To learn more about the average from the given link
https://brainly.com/question/21151502
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