Question

. In a hostel there are 125 students, out of which 80 drink tea, 60 drink coffee and 20 drink tea and coffee both. Find the number of students who drink tea or coffee.​

Answer 1

Answer:

the number of students who drinks tea and coffee both are 20 students.

Answer 2

Answer:

i. Let U be the set of students in the hostel, T be the set of students who drink tea and C be the set of students who drink coffee.

n(U) = 125, n(T) = 80, n(C) = 60,

Number of students who drink Tea and Coffee = n(T ∩ C) = 20

ii. n(T ∪ C) = n(T) + n(C) – n(T ∩ C)

= 80 + 60 – 20

∴ n(T ∪ C) = 120

∴ 120 students drink tea or coffee Also, there are 125 students in the hostel.

Number of students who do not drink tea or coffee

= n(U) – n(T ∪ C) = 125 – 120 = 5

∴ 5 students do not drink tea or coffee.

I Hope your help