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

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.