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Determine the Last Digit (Posted on 2024-11-17)

Determine(with proof) the last digit of 2^2ⁿ for n ≥ 2.

No Solution Yet Submitted by K Sengupta

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Answer

Comment 2 of 2 |

For all n>=2, 2^n is divisible by 4. Let 2^n=4x. Then, 2^(2^n)=2^(4x)=(2^4)^x=16^x. All powers of 16 end in 6. Therefore, 2^(2^n) ends in 6.

Posted by Math Man on 2024-11-17 18:33:00

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