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how many four-digit, positive integers are there where each digit is a prime number?

Logic  Oct 6, 2018

Best Answer 

 #1
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+1

Well, I can only think of 4 prime numbers: 2,  3,  5,  7

2357 =4! =24

 

{2, 3, 5, 7} | {2, 3, 7, 5} | {2, 5, 3, 7} | {2, 5, 7, 3} | {2, 7, 3, 5} | {2, 7, 5, 3} | {3, 2, 5, 7} | {3, 2, 7, 5} | {3, 5, 2, 7} | {3, 5, 7, 2} | {3, 7, 2, 5} | {3, 7, 5, 2} | {5, 2, 3, 7} | {5, 2, 7, 3} | {5, 3, 2, 7} | {5, 3, 7, 2} | {5, 7, 2, 3} | {5, 7, 3, 2} | {7, 2, 3, 5} | {7, 2, 5, 3} | {7, 3, 2, 5} | {7, 3, 5, 2} | {7, 5, 2, 3} | {7, 5, 3, 2} (total: 24)

Guest Oct 7, 2018
 #1
avatar
+1
Best Answer

Well, I can only think of 4 prime numbers: 2,  3,  5,  7

2357 =4! =24

 

{2, 3, 5, 7} | {2, 3, 7, 5} | {2, 5, 3, 7} | {2, 5, 7, 3} | {2, 7, 3, 5} | {2, 7, 5, 3} | {3, 2, 5, 7} | {3, 2, 7, 5} | {3, 5, 2, 7} | {3, 5, 7, 2} | {3, 7, 2, 5} | {3, 7, 5, 2} | {5, 2, 3, 7} | {5, 2, 7, 3} | {5, 3, 2, 7} | {5, 3, 7, 2} | {5, 7, 2, 3} | {5, 7, 3, 2} | {7, 2, 3, 5} | {7, 2, 5, 3} | {7, 3, 2, 5} | {7, 3, 5, 2} | {7, 5, 2, 3} | {7, 5, 3, 2} (total: 24)

Guest Oct 7, 2018

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