In a group of 100 students, every student studies 8 subjects and every subject is studied by 10 students. The number of subjects is:
AExactly 50
BExactly 30
CExactly 90
DExactly 80
Answer & Solution
Correct answer: D. Exactly 80
1. Total student-subject pairings = 100 students x 8 subjects = 800.
2. Each subject is taken by 10 students, so subjects = 800 / 10.
3. Number of subjects = 80.
_Source: RRB Group D CEN-02/2018 PYQ, Q.51._
Related questions