Question

In an examination, there are three subjects A, B and C. A student has to pass in each subject. 20% students failed in A, 22% students failed in B and 16% failed in C. The total number of students passing the whole examination lies between 

(a) 42% and 84% (b) 42% and 78% (c) 58% and 78% (d) 58% and 84%

Answer 1

(a) Pass % is minimum when failure % is maximum. 

Maximum % of failure = 20 + 22 + 16 = 58% 

∴ Minimum pass % = 100 – 58 = 42% 

Now, pass % is maximum, when failure % is minimum. 

Minimum % of failure = 16% 

(∵ 22 % failure covers both 16% and 20% i.e, 22% is the minimum value of failure %).  

∴ Maximum % of passing = 100 – 16 = 84% 

Hence, pass % range = 42% to 84%.