The airmail rates to a country are shown.
Type | Mass | Cost |
Letters |
First 8 g | 20z¢ |
Every additional 4 g or less | 12z¢ | |
Postcards | Per piece | 40¢ |
Perry sent 4 postcards and a letter. The letter weighed 15 g. How much did Perry pay in total? Give your answer in terms of z in the simplest form.