What is the unit digit in {(6374)¹⁷⁹³ x (625)³¹⁷ x (341⁴⁹¹)}?

Explanation:-

Unit digit in (6374)¹⁷⁹³ = Unit digit in (4)¹⁷⁹³
    = Unit digit in [(4²)⁸⁹⁶ x 4]
    = Unit digit in (6 x 4) = 4
Unit digit in (625)³¹⁷ = Unit digit in (5)³¹⁷ = 5
Unit digit in (341)⁴⁹¹ = Unit digit in (1)⁴⁹¹ = 1
Required digit = Unit digit in (4 x 5 x 1) = 0.