Given:
Total number of students = 40
From the circle graph given, let's determine the number of students that received Bs or Cs.
Given:
Percentage of students that received Bs = 30%
Percentage of students that received Cs = 40%
Percentage of student that received Bs or Cs = 40% + 30% = 70%
Thus, to find the number of students who received Bs or Cs, we have the equation below:
No of students who received Bs or Cs = (% of students who received Bs or Cs) x (Total n0 of students)

Thus, we have:

Therefore, the number of students who received Bs or Cs are 28
ANSWER:
C. 28