Question 25
Carl computes the number
$$
N=5^{555}+6^{666}+7^{777}
$$
and writes it in decimal notation. What is the last digit of $N$ that Carl writes?
$$
N=5^{555}+6^{666}+7^{777}
$$
and writes it in decimal notation. What is the last digit of $N$ that Carl writes?