Question

These are 20 students in a Chemistry class and 30 students in a physics class. Find the number of students which are either in physics class or Chemistry class in the following cases :
i. Two Classes meet at the same hour
ii. The two classes met at different hours and 10 students are enrolled in both courses
{CLASS 11 SETS}​

Answer 1

Answer:

Step-by-step explanation:

a) Two classes meet at the same hour :

n(C∩P) = n(C) + n(P)

n(C) = 20

n(P) = 30

= 20 + 30 = 50

b)when two classes meet differently

n(C∪P) = n(C) + n(P) - n(C∩P)

n (C∩P) = 10

= 20 + 30 - 10 = 40