In a class of 60 students, 40 opted for NCC, 30 opted for NSS and 20 opted for both NCC and NSS. If one of these students is selected at random, then the probability that the student selected has opte

Question

In a class of 60 students, 40 opted for NCC, 30 opted for NSS and 20 opted for both NCC and NSS. If one of these students is selected at random, then the probability that the student selected has opted neither for NCC nor for NSS is :

TestHub · Accepted Answer

Let A & B be the sets for NCC and NSS respectively. Given n A = 40 , n B = 30 , n A ∩ B = 20 ∴ n A ∪ B = n A + n B - n A ∩ B = 40 + 30 - 20 = 50 ∴ P A ∪ B = 50 60 = 5 6 ∴ P A ∪ B ′ = 1 - P A ∪ B = 1 - 5 6 = 1 6

Mathematics - Probability Question with Solution | TestHub

Options:

Doubts & Discussion