self Maths Puzzle

what remainder comes (6)^17+(17)^6 is divisible by 7

Read Solution (Total 2)

self Other Question

How many natural number not exceeding 4321 can be formed with the digits 1,2,3 and 4 if the digits can repeat.

(PLEASE GIVE PROPER EXPLANATION)
if (13!*16-13!*8)/(8*13!-4*13!)=a. what is a/(13!*4)?