## 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 ?

by BTGmoderatorDC » Thu Jan 06, 2022 9:01 pm

00:00

A

B

C

D

E

## Global Stats

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

by swerve » Sat Jan 08, 2022 8:19 am

00:00

A

B

C

D

E

## Global Stats

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

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