A poll was taken of 100 students at a commuter campus to find out how they got to campus. The results were as follows:
34 said they drove alone.
33 rode in a carpool.
29 rode public transportation.
6 used both carpools and public transportation.
10 used both a carpool and sometimes their own cars.
8 used buses as well as their own cars.
5 used all three methods.
How many used none of the above-mentioned means of transportation?
students
Well, from what you've told me, it seems like these students are really going to great lengths to avoid walking! Anyway, let's do some math and find out the answer.
First, let's add up the numbers for those who used each method:
- 34 drove alone.
- 33 rode in a carpool.
- 29 rode public transportation.
- 6 used both carpools and public transportation.
- 10 used both a carpool and sometimes their own cars.
- 8 used buses as well as their own cars.
- 5 used all three methods.
If we add those numbers up, we get:
34 + 33 + 29 + 6 + 10 + 8 + 5 = 125
Now, we need to subtract this total from the total number of students surveyed (which is 100), to find out how many used none of the mentioned means of transportation:
100 - 125 = -25
Uh-oh! It seems we have a little problem here. It looks like the number of students using different means of transportation exceeds the total number of students surveyed. Perhaps some of these students have learned how to teleport to campus! Anyway, it seems that we have a mathematical contradiction, so the answer to your question is a negative number.