55\(\frac{1}{3}\)%
60%
65%
66\(\frac{2}{3}\)%
Correct answer is D
Percentage of students with marks ranging from 35 to 50 = \(\frac{f_{35} + f{40} + f{50}}{\sum f}\)
= \(\frac{35 + 40 + 45}{20 + 35 + 40 + 45 + 25 + 15}\) x 100%
= \(\frac{120}{180}\) x 100%
= 66\(\frac{2}{3}\)%