Four dice are thrown simultaneously. Find the probability that two of them show the same face and remaining two show the different faces.

A  4/9

B 5/9

C 11/18

D 7/9

Solution

Correct Answer: Option B

Select a number which ocurs on two dice out of six numbers (1, 2, 3, 4, 5, 6). This can be done in \({}^6C_1\) ways.

Now select two distinct number out of remaining 5 numbers which can be done in \({}^5C_2\) ways. Thus these 4 numbers can be arranged in 4!/2! ways.

 

So, the number of ways in which two dice show the same face and the remaining two show different faces is 

\({}^6C_1\times{}^5C_2\times\frac{4!}{2!}=720\)

 =>  n(E) = 720

= \(\therefore P\left(E\right)=\frac{720}{6^4}=\frac59\)

Practice More Questions on Our App!

Download our app for free and access thousands of MCQ questions with detailed solutions