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Five different marbles are placed in 5 different boxes randomly. Then the probability that exactly two boxes remain empty is

a. 2/5
b. 12/25
c. 3/5
d. none of these

User Dah
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1 Answer

7 votes

Final answer:

To find the probability that exactly two boxes remain empty, we need to consider the number of ways we can choose the two empty boxes. There are 5 choose 2 ways to select two boxes out of five. Once we have chosen the empty boxes, there are 3! * 5! ways to distribute the marbles. Therefore, the probability is 3/5.

Step-by-step explanation:

To find the probability that exactly two boxes remain empty, we need to consider the number of ways we can choose the two boxes that remain empty. There are 5 choose 2 ways to select two boxes out of five. Once we have chosen the two empty boxes, there are 3! = 6 ways to distribute the five marbles into the remaining three boxes. However, since the marbles are different, we need to multiply this by 5! = 120 to account for the different arrangements of the marbles.

Therefore, the total number of favorable outcomes is (5 choose 2) * 6 * 120 = 60 * 6 * 120 = 43200. The total number of possible outcomes is 5^5 = 3125. So, the probability is 43200/3125 = 3/5.

User Corvax
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