Verified Answer :

In the first digit, there are 6 possibilities. In the second, there are 5, because you can't use the digit you used before. In the third, there are 4, and in the fourth, there are 3. So, 

654*3=360

There are 360 different possible four-digit numbers

Answer:

C. 6P4 = 360

Step-by-step explanation:

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