For these problems, assume a sales tax rate of $5$ %.

5.1)

The price of a shelving unit is $$40$ before tax. What’s the price you have to pay when you add the tax?

5.2)

A shopkeeper wants to be left with $$30$ after selling a certain jacket. That means he wants the jacket to cost $$30$ before tax. What will his customers have to pay for the jacket?

5.3)

A pair of trousers costs $$30.45$ including tax. What’s the price before tax?

5.4)

A dress used to cost $$20$, and its price increased by a growth factor of $1.15$. What’s the new price of the dress?

You can find the solutions here.