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'.]

All you really care about is the last digit in each of the calculations:
8^7 = 2097152
2^6 = 64
4^5 = 1024
4^4 = 256
6^3 = 216
6^2 = 36
6^1 = 6
Last digit is 6.
Did I understand the problem correctly?

Posted by Kerry Graham on 2004-01-06 11:00:28