In a class of 80 students, every student had to study Economics or Geography or both Economics and Geography. lf 65 students studied Economics and 50 studied Geography, how many studied both subjects?
A
15
B
30
C
35
D
45
E
50
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Applying the formula
80 = 65 - x + x + 50 - x
x = 35
Source: Myschool Past Questions Archive (Record #22928)