The Last Digit: Find it

Number Theory Level 2

Find the last digit of $8^{1232298968}$ .

1 solution

Noam Pirani
Apr 25, 2016

Notice that $8^4=6 (mod 10)$ , and 4 divides the exponent since $68=0 (mod 4)$ . Now since $6^n=6 (mod 10)$ for all $n$ , we are done.

Yeah. The same sol.

Abhiram Rao - 5 years, 1 month ago

I think you should use the congruent sign instead of equality while doing Modular Arithmetic.

Silver Vice - 5 years, 1 month ago

Yeah. Maybe the latex mistake.

Abhiram Rao - 5 years, 1 month ago

Note: the $LaTex$ for $\pmod{}$ sign is \pmod{ number }

Bloons Qoth - 4 years, 10 months ago