Probability Question 137

Question: If a dice is thrown twice, the probability of occurrence of 4 at least once is

[UPSEAT 2003]

Options:

A) $ \frac{11}{36} $

B) $ \frac{7}{12} $

C) $ \frac{35}{36} $

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

Probability of occurrence of 4 $ =\frac{1}{6} $

Probability of inoccurrence of ‘4’ $ =\frac{5}{6} $

$ \therefore $ Required probability $ ={{}^{2}}C_1( \frac{1}{6} )( \frac{5}{6} )+{{}^{2}}C_2{{( \frac{1}{6} )}^{2}}{{( \frac{5}{6} )}^{0}}=\frac{11}{36} $ .