Statistics And Probability Question 22
Question: Rajesh doesn’t like to study. Probability that he will study is 1/3. If the studied then probability that he will fail is1/2 and if he didn?t study then probability that he will fail is 3/4 if in result Rajesh failed then what the probability that he didn’t studies is.
Options:
A) 2/3
B) 3/4
C) 1/3
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
- [b] He will fail in exam in two cases: Case (i) He studied and failed, probability of this case is (1/3) (1/2) =1/6. Case (ii) He didn?t studied and failed, probability of this case is (2/3) (3/4) = ½. So total probability is $ 1/6+1/2=4/6=2/3 $ Then required probability $ =(1/2)(2/3)=3/4. $
BETA
