OK I think I can post my riddle now...I hopefully worked out anything that might have been wrong with it but we will see....Since most of you are fantasy adventurers I will tailor it to you guys.....
You and your party are found in the dungeon and need to proceed through this locked door. The door can only be opened when you figure out the riddle. Inscribed on the door is the following passage
"This door will only open under the correct weight." Under this passage you see that 41.5 kilograms in written in the door also. Next to the door is a platform, that you assume is the scale, 3 jugs, and a small pound. Your party has already figured out that 1 gallon of water is equal to 2.5 kilograms, and that each jar weighs the same (500 grams), but holds different amounts of water. Jar A can only hold 10 gallons, Jar B can only hold 5, and Jar C can only hold 3 gallons of water. You must figure out how to get exactly 41.5 kilograms on the scale with using the water and the jars. Good Luck.