UPSC 2015 CDS I Math Paper

Remainder when 1421 is divided by 12 = 5
Remainder when 1423 is divided by 12 = 7
Remainder when 1425 is divided by12 = 9
∴ Remainder when 1421×1423×1425 is divided by 12
= Remainder when 5×7×9=315 is divided by 12
=3