Toreador (9/26/2011)
Good question - shame there weren't more possible answers given, I only had to look at the first two, and would probably have got at least one of the others wrong if I'd had to guess at them!
Or, you could have just looked at "C" and saw that '2' + '3' + 1 = 24 and none of the other possible answers had 24 as the answer. That excluded all others without even having to calculate anything else.