This is a good innumaracy test. The level to which it pisses you off is a good indicator of how well (or rather, poorly) you understand how money works. It's

This is a good innumaracy test. The level to which it pisses you off is a good indicator of how well (or rather, poorly) you understand how money works. It's along the same lines as telling somebody that it costs more than $0.01 to make a penny.