How do you determine the mass without counting all the items inside?

Question

Lab Objective: To determine the mass, in gramss, of your bag without counting all of the items individually. Rules-1.You may weigh up to 5 items that represent each bag. 2.Bags cannot be opened and counted indivdually.

Someone told me theres a formular to find this please just give me that.

Freakin idiot you cant weigh the bag.

Answer 1

Weigh the whole bag.

What items "represent" the bag?

Where does it say you can't weight the whole bag, except in your tirade afterthought?

Answer 2

First estimate the volume of the contents of the bag.

Second calculate the density of each of the items that make up the contents of the bag (i.e. mass / volume of each item). Take the average density assuming that they are different.

Multiply the estimated volume of the contents of the bag by the estimated average density of the contents of the bag. This will give you the estimated mass.

(equation: mass = volume x density)

Without more specific information, this is about all I can tell you.
(By the way, take it easy on the first answerer, you didn't specify that you couldn't weigh the bag as one of your rules)