Arithmetic Ability
 Probability

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Q.

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

View Answer

Correct choice: B

Explanation:

Select a number which ocurs on two dice out of six numbers (1, 2, 3, 4, 5, 6). This can be done in C16 , ways. Now select two distinct number out of remaining 5 numbers which can be done in C25 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 C16×C25×4!/2!=720 => n(E) = 720 ∴P(E)=720/64=5/9
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