What's the fastest way to do these math problems?

pckeller
Tue, 01 Dec 2009 16:40:56 +0000

For climber,swimmer problem – you were just about done once you knew there were 80 climbers and only 40 non swimmers…Since there are only 40 non-swimmers available, best case is that all of them happen to be climbers, so of the 80 climbers, at least 40 have to be swimmers (again, because there were only 40 non-swimmers available).