The airmail rates to a country are shown.
Type | Mass | Cost |
Letters |
First 16 g | 22k¢ |
Every additional 8 g or less | 10k¢ | |
Postcards | Per piece | 80¢ |
Perry sent 4 postcards and a letter. The letter weighed 21 g. How much did Perry pay in total? Give your answer in terms of k in the simplest form.