Probability Question 51
Question: 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=5 $
or (ii) Three $ 2’s $ and two $ 3’s={}^{5}C_2=10 $
Hence, the required probability $ =\frac{15}{6^{5}}=\frac{5}{2592}. $
BETA
