Q1: The last day of a century cannot be

ANS:C - Tuesday

100 years contain 5 odd days.  Last day of 1^st century is Friday. 200 years contain (5 x 2)  3 odd days.  Last day of 2^nd century is Wednesday. 300 years contain (5 x 3) = 15  1 odd day.  Last day of 3^rd century is Monday. 400 years contain 0 odd day.  Last day of 4^th century is Sunday. This cycle is repeated.  Last day of a century cannot be Tuesday or Thursday or Saturday.