For which of the following values of n would the units digit of n be e

Question

For which of the following values of n would the units digit of n be equal to the units digit of n^3 ?

I. 4
II. 5
III. 6

A. I only
B. II only
C. III only
D. I and III only
E. I, II, and III

chetan2u · Answer

Irrespective of power, the units digit of N raised to any power will remain the same when the units digit of N is: 0, 1, 5 and 6.

Both 5 and 6 are in E only, so E is the answer.

rvgmat12 · Answer

4^3 - 64 - yes
5^3 - 123 - yes
6^3 - 216 - yes

E.

Palak74 · Answer

Answer option E

4^3=64 
5 ^any number will give units digit 5 
6 ^ any number will give units digit 6

CrackverbalGMAT · Answer

Solution:

Lets start with I.

I. 4 => 4^3 = 6 (4)

=>Unit digit of n is same as that for n^3 (B & C can be eliminated)

II. 5 => 5^3 =12 (5)

=> Unit digit of n is same as that for n^3 (A & D can be eliminated)  (option (e) )

Devmitra Sen
GMAT SME

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