Algebra with applications
posted by Kim .
A poll was taken of 100 students at a commuter campus to find out how they got to campus. The results were as follows:
said they drove alone.
rode in a carpool.
rode public transportation.
used both carpools and public transportation.
used both a carpool and sometimes their own cars.
used buses as well as their own cars.
used all three methods.
How many used none of the above-mentioned means of transportation?