Last year for Christmas, I got a stocking stuffer that was a day-by-day calendar with brain teasers. It's produced by Mensa, supposedly. The brain teasers mostly consist of word problems, and I've found any number of mistakes. But today's takes the cake. Here it is:

If Charlie were one year older, he would be half Pat's age. In two years, he will be half her age then. How old are they now? (Hint: Neither one is yet a teenager.)

Can anyone else find the problem with this word problem? (It's not a grammar issue.)