Solution:Let total number of students be 100.In A → Fail students = 20 and Pass students = 80
In B → Fail students = 22 and Pass students = 78
In C → Fail students = 16 and Pass students = 84
Maximum number of students who pass all the three subjects
= 78 + 78 + 78 = 234
Minimum number of students who fail in all three subjects
= 42 + 42 + 42 = 126.
Maximum percentage = (234 × 100)/300 = 78%
Minimum percentage = (126 × 100)/300 = 42%