In a class of 80 students, every students studies Economics or Geography or both. If 65 students study Economics and 50 study Geography, how many study both subjects?
A
15
B
30
C
35
D
45
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Let c = no of students that offered both subjects
\(\therefore\) No of students offering Economics = 65 - c
No of students offering Geography = 50 - c
65 - c + c + 50 - c = 80
115 - c = 80
c = 35
35 students offer both Economics and Geography.
Source: Myschool Past Questions Archive (Record #26475)