Correct Answer:
A. 20
The total cost is (3*16) + (4*23) = 48 + 92 = 140. With 7 books in total, the average price is 140/7 = 20. The other options are incorrect calculations.
The total cost is (3*16) + (4*23) = 48 + 92 = 140. With 7 books in total, the average price is 140/7 = 20. The other options are incorrect calculations.