Answer: $0.30 per dozen.
Explanation:
Given: The whole cost of 13 dozen pencils = $9
If 3 dozen broke in transit, remaining dozens of pencils = 13-3 = 10 dozens
Also, Selling price of theses 10 dozens =
[given]

Then, the selling price of each dozen =

Hence, the shopkeeper sells the remaining pencils at $0.30 per dozen.