JMO STD V and STD VI - divisibility

What is the unit digit in (6324)¹⁷⁹⁷ × (615)³¹⁶ × (341)⁴⁷⁶

^{JMO STD V and STD VI}

^Answer:

(6324)^3]1797 = (.....4)^3}599 = (....4)^3]199 x (...4) x (...4) 

= (...4)^3]66  x (...4) x (..4) x (...4)
= (...4)^3]22 x (...4) =  (...4)^3]7 x (...4) x (...4)
=  (...4)^3]2 x (...4) x (...4) x (...4)
=  (...4)² x (...4) 
= (...4)

(615)³¹⁶ = (.....5)

(341)⁴⁷⁶  = (....1)

SO, answer: (....4) x ( ...5) x (...1) = 0