Find the units digit of \(556^{17n}+339^{5m+15n},\) where \(m\) and \(n\) are positive integers.

[Vincen]

Find the units digit of \(556^{17n}+339^{5m+15n},\) where \(m\) and \(n\) are positive integers.

(1) \(4m+12n=360\)
(2) \(n\) is the smallest \(2\)-digit positive integer divisible by \(5.\)

Answer: A

Source: e-GMAT