You are given that $3^{400}\equiv 1\pmod{1000}$. What are the last three digits of $3^{12000}$?
Question:
You are given that $3^{400}\equiv 1\pmod{1000}$. What are the last three digits of $3^{12000}$?
Answer:
Let's think step by step.

user
001
You are given that $3^{400}\equiv 1\pmod{1000}$. What are the last three digits of $3^{12000}$?
train