To compare 3+ groups you can use the following formala:
Total = (Group 1) + (Group 2) + (Group 3) - (# of people who take 2 classes) - 2x(# of people who take all 3 classes) + (# who take neither)
Total = (50) + (35) + (40) - (15 + 10 + 12) - (none) - (none)
Total = 125 - 37
Total = 88
B
Total = (Group 1) + (Group 2) + (Group 3) - (# of people who take 2 classes) - 2x(# of people who take all 3 classes) + (# who take neither)
Total = (50) + (35) + (40) - (15 + 10 + 12) - (none) - (none)
Total = 125 - 37
Total = 88
B
![Mumford & Sons – Blind Leading the Blind – Single [iTunes Plus M4A]](http://is1-ssl.mzstatic.com/image/thumb/Music124/v4/49/c3/83/49c38304-45c6-20d0-c6df-3b36ea8bd92a/19UMGIM89194.rgb.jpg/316x316bb.webp)
