In a survey, 160 students were selected and asked to write down their favorite subjects in high school.

The breakdown of the survey was as follows:

100 students chose Math
110 students chose Biology
90 students chose Chemistry
65 students chose Math and Biology
54 students chose Biology and Chemistry
43 students chose Math and Chemistry
20 students chose Math, Biology and Chemistry

1. How many students did not choose Chemistry?

2. How many chose Biology only?

3. How many chose Chemistry only?

4. How many students chose Math and Chemistry but not Biology?

5. How many students chose Math and Biology but not Chemistry?

6. How many chose Math only?

7. How many students did not choose any of the 3 given subjects?