Statistics And Probability Question 17
Question: In a class 30% students like tea, 20% like coffee and 10% like both tea and coffee. A student is selected at random then what is the probability that he does not like tea if it is known that he likes coffee?
Options:
A) 1/2
B) 3/4
C) 1/3
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
- [a] Let P [a] = Probability that a randomly selected student likes tea = 0.3. Let $ P(A_2)= $ Probability that a randomly selected student does not like tea = 1 - 0.3 = 0.7. Let P [b] = Probability that a randomly selected student likes coffee = 0.2
$ \therefore P(A_2\cap B)=P(B)-P(A\cap B)=0.2-0.1=0.1 $ Now we have to find $ P(A_2/B)=P(A_2\cap B)/p(B)=0.1/0.2=1/2 $
BETA
