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Determine the Last Digit (Posted on 2024-11-17) Difficulty: 1 of 5
Determine(with proof) the last digit of 22n for n ≥ 2.

No Solution Yet Submitted by K Sengupta    
Rating: 5.0000 (1 votes)

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Solution solution (spoiler) | Comment 1 of 2
The first three powers of 2 end in 2, 4, 8, 6. The next one returns to 2, and that begins the next cycle of four members.

2^n where n>1 will always be a multiple of 4, so no matter how high 2^n gets, the exponent will be a multiple of 4, and you'll be at the fourth member of the cycle: 6.

  Posted by Charlie on 2024-11-17 10:51:38
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