A poll was taken of 100 students at a commuter campus to find out how they got to campus. The results were as follows:

27 said they drove alone.
30 rode in a carpool.
34 rode public transportation.
4 used both carpools and public transportation.
3 used both a carpool and sometimes their own cars.
4 used buses as well as their own cars.
1 used all three methods.
How many used none of the above-mentioned means of transportation?

I answered the "same" question yesterday.

Just use your numbers and follow my method

http://www.jiskha.com/display.cgi?id=1381287210