Question

Out of 100 students, 10 students used to drink milk(M), coffee(C) and Tea(T); 20M and C; 30C and T; 25M and T; 12M only; 5C only and 8T only. The number of students who did not drink any of this is

a) 18

b) 24

c) 20

d) 16

Answer 1

Number of student who drinks at least one of them =12+5 + 8 + 10 + 20 +15 +10 =80

Hence,Number of student who did not drink any of this = 100 - 80 =20

 

Hence,Option (C) 20 is the correct chocie.

Comments

Could you please tell me that this type of problems fall under what category ? and when we say that x people drink tea and cofee and y people drink tea then doesn't x include some part of y?So how can we simple add both of them ?

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These types of problem falls in  Set Theory.

and there is difference between x drinks coffee and x drinks " only " coffee.Please read question carefullly.