Math
posted by Shaakira on .
Find the remainder when 1!+2!+...+299!=300! is divided by 21 using mod 0 in base 21.

See solution to the same problem at:
http://www.jiskha.com/display.cgi?id=1343870534
and
http://www.jiskha.com/display.cgi?id=1343870950