Pepsi Math: Oh, the Madness

The Pepsi math's still bugging me:

290cal / 20oz =14.5 cal/oz
230cal / 16oz = 14.375 cal/oz.

Yet, their info panel says that a serving size is 8oz and said serving size contains 110cal (or, 13.75 cal/oz.). It's a tiny thing. It might even be a genuine error. But I loathe unexplained inconsistencies.

Probably just some marketer's backhanded way to get people to call in (or the labeling department's way of seeing if anyone actually reads the labels). ARGH!