Answer:
6
Step-by-step explanation:
We want to find the units digit of [tex]2^{4000}[/tex]. Let's first look for a pattern:
[tex]2^{1}=2[/tex]
[tex]2^{2}=4[/tex]
[tex]2^{3}=8[/tex]
[tex]2^{4}=16[/tex]
[tex]2^{5}=32[/tex]
[tex]2^{6}=64[/tex]
[tex]2^{7}=128[/tex]
[tex]2^{8}=256[/tex]
...and so on
Notice the units digits: 2, 4, 8, 6, 2, 4, 8, 6, ... It repeats every four!
This means that for every exponent of 2 that is a multiple of 4 (like 4000 in the problem), the units digit will always be the fourth number in the repeating pattern: 6.
The answer is thus 6.
~ an aesthetics lover
