From an Introduction to Programming with C++ Ch2 Exercise 14. Dont understand. They say the algorithm is when and I need to change it, but when you run the sample numbers through they work. Confused and a little lost. Any help would be great. Thanks.

Should calculate the total amount due algorithm apparently wrong please help

1. enter the number purchased and folder price

2 calculate the subtotal by multiplying the number purchased by the folder price

3 calculate the sales tax by dividing the subtotal by the sales tax rate

4 calculate the sales tax due by adding the sales tax to the subtotal

5. display the total due

use 20 for folders purchase, use $.25 for price of each folder, and .045 for sales tax rate

what is wrong with the algorithm