document.write( "Question 1137641: Find the unit digit of 64^401 \n" ); document.write( "

Algebra.Com's Answer #755479 by ikleyn(52814) $\"\"$ $\"About$

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document.write( "The units digit of numbers 64, 64^2, 64^3, 64^4, 64^5  and so on form the cyclic sequence 4, 6, 4, 6, 4 . . . . and so on.\r\n" );
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document.write( "The length of the cycle is 2; each even-indexed number in this cycle is 6; each odd-indexed number in this cycle is 4.\r\n" );
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document.write( "So, the answer to the problem's question is 4  (since the degree index 401 is an odd number).\r\n" );
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