What is the last digit of the number:

8^(7^(6^(5^(4^(3^(2^1))))))

[(a)^b implies 'a' raised to the power of 'b', ((a)^b)^c implies 'a' raised to the power 'bc', but a^(b^c) implies 'a' raised to the power 'b' raised to the power 'c'.]

It must be either 2 or 8, for all odd powers of 8 end with one of these numbers.

Posted by Federico Kereki on 2003-12-31 09:58:58