If n is a one-digit positive integer, what is n ?

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If n is a one-digit positive integer, what is n ?

(1) The units digit of 4^n is 4.
(2) The units digit of n^4 is n.


OA E

Source: Manhattan Prep

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BTGmoderatorDC wrote:
Thu Jan 06, 2022 9:01 pm
If n is a one-digit positive integer, what is n ?

(1) The units digit of 4^n is 4.
(2) The units digit of n^4 is n.


OA E

Source: Manhattan Prep
\(n={1,2,3,4,5,6,…9}\)

1) Insufficient
\(4^n\) units \(4: n={1,5,9}\)

2) Insufficient
\(n^4\) units \(n: n={1,5,6}\)

1 and 2 combined, insufficient
\(n={1,5}\)

Therefore, E