Question

Everyone at your school has to take one art class, so 115 students take glass blowing, 90 students take cave painting, and 15 students take both. The wisest 120 students take photography for an easy A. How many total students are at your school?​

Answer 1

There are 340 students at your school.
115 + 90 + 15 + 120 = 340

Answer 2

• A=115
• B=90
• A
  `\cap` B=15

So

• AUB=A+B-(A$\cap$ B)
• AUB=115+90-15
• AUB=100+90
• AUB=190

Total students

• 190+120
• 310