document.write( "Question 487120: which of the following could be the units digit of 57^n where n is a positive integer? Indicate all such digits:
\n" ); document.write( "A.) 0
\n" ); document.write( "B.) 1
\n" ); document.write( "C.) 2
\n" ); document.write( "D.) 3
\n" ); document.write( "E.) 4
\n" ); document.write( "F.) 5
\n" ); document.write( "G.) 6
\n" ); document.write( "H.) 7
\n" ); document.write( "I.) 8
\n" ); document.write( "J.) 9
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #333087 by richard1234(7193) $\"\"$ $\"About$

You can put this solution on YOUR website!
Same units digits as 7^n. 7^1 ≡ 7 (mod 10), 7^2 ≡ 9, 7^3 ≡ 3, 7^4 ≡ 1, 7^5 ≡ 7, and the pattern repeats. The only possible digits are 1,3,7,9. \n" ); document.write( "

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