SOLUTION:
We want to use the Venn diagram to answer the following questions;
1. How many instruments are not taught on a Wednesday;
This is gotten from the instruments outside the circle labeled 'Played on a Wednesday'.
This is Guitar,Bass and Zither;
b. The instruments taught on both Monday and Wednesday, this is the intersection of the two circles, the instruments are Sax and Harp, thus the answer is;
c. Instruments taught on neither Monday nor Wednesday, these are the instruments outside the two circles. They are;