Here's the question you clicked on:
traininator
Suppose you have a large coffee can full of pennies. How can you estimate how much money the can contains without counting all the coins? (Hint: What is the relationship between the mass of pennies and the number of pennies?)
Suppose you cut off one foot and weigh it. Then you cut off your other foot and put it on the scale. How much do both feet probably weigh together?
Suppose I have a keg filled with monkey brains. Now if I know 1 monkey brain is 5 pounds and I weigh the keg and it weighs 20 pounds, I know there are 4 brains in the keg because each one weight 5 pounds. 20 pounds of brains divided by 5 pounds per brain gives you 4 brains.
what the hell man just answer my question and stop being wierd
To answer your hint: density.
can someone please just give me the answer -_-
I would weigh the can of pennies. I would then weigh the can. Subtract the weight of the can from the combined weight giving you the weight of the pennies. Then weigh one penny. Do the appropriate math and get an answer which will be accurate if all the pennies are consistent.
Haha, yeah. The thing is, you have a certain number of pennies, say n (pennies). Each one has a weight, say w (in ounces). Then your total weight of the cup is the number of pennies times the weight of one. Say the total weight is t. Then\[t=n*w\] Therfore you can solve for n (number of pennies) \[n=\frac{t}{w}\]
You're welcome, and please note there may be other methods.
Methods that involve cutting off feet and weighing monkey brains?
In practice, however, you would need to know the weight of the can. It would be part of the total weight, t.
\[numberOfPennies = \frac{weight Of Pennies + weightOfCan}{weightPerPenny}\]
Since the can contains a certain amount of pennies, of which some may be a rare collectors item, the amount of money they are worth is debatable.
Thank you @theEric for the only truly sensible (and correct) answer in this thread. Medal to you good sir.