The airmail rates to a country are shown.
Type | Mass | Cost |
Letters |
First 20 g | 30x¢ |
Every additional 10 g or less | 6x¢ | |
Postcards | Per piece | 80¢ |
Sam sent 5 postcards and a letter. The letter weighed 42 g. How much did Sam pay in total? Give your answer in terms of x in the simplest form.