"Hector knocked up three girls in his gang. There are 27 girls in his gang. What is the exact percentage of the girls in the gang that Hector knocked up?"
The sales tax in DC is 5 3/4%. My old record turntable runs at 33 1/3 rpm. Even if my PC is pretty stupid about thinking that fractions have to be decimal, and imagines that "1+1=3 for sufficiently large values of 1", I haven't forgotten how to handle them.