Statistics And Probability Question 220
An ordinary cube has four blank faces, one face marked 2, another marked 3. Then the probability of obtaining a total of exactly 12 in 5 throws, is
Options:
A) $ \frac{5}{1296} $
B) $ \frac{5}{1944} $
C) $ \frac{5}{2592} $
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
-
$ n= $ Total number of ways $ =6^{5} $ $ A $ total of 12 in 5 throw can be obtained in following two ways ? (i) One blank and four $ 3's={}^{5}C_1 \times 1^4 \times 1=5 $ or (ii) Three $ 2's $ and two $ 3's={}^{5}C_2 \times 1^3 \times 1^2=10 $ Hence, the required probability $ =\frac{15}{6^{5}}=\frac{5}{2592}. $
BETA
