This document provides steps to calculate how much cash in $10 bills can fit in a 30 liter backpack. It determines that 25,000 $10 bills would take up a volume of 26,250 cubic centimeters, which is less than the 30 liter (30,000 cubic centimeter) capacity of the backpack. Therefore, $250,000 in $10 bills could be stashed in the backpack.