Everyone in a class of 35 students takes math and history. 8 students received an A in history, 15 received an A in math and 3 received an A in both courses. How many students did not receive an A in either course?
OOPS mistake fixed
8 students in history
15 students in math
8 + 15 = 23
23 - 3 who recieved both = 20 people who recieved an A
Knowing that 20 people recieved an A in history and/or math. How many students did not recieve an A in either course?
(Hint: It's 2 second mental-math)