## traininator Group Title 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?) 2 years ago 2 years ago

1. Kainui Group Title

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?

2. traininator Group Title

what???

3. Kainui Group Title

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.

4. traininator Group Title

what the hell man just answer my question and stop being wierd

5. PurpleNose Group Title

6. traininator Group Title

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.

8. traininator Group Title

thanks

9. theEric Group Title

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.

11. Kainui Group Title

Methods that involve cutting off feet and weighing monkey brains?

12. theEric Group Title

In practice, however, you would need to know the weight of the can. It would be part of the total weight, t.

13. theEric Group Title

$numberOfPennies = \frac{weight Of Pennies + weightOfCan}{weightPerPenny}$

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.

15. theEric Group Title

Very true.

16. jagatuba Group Title

Thank you @theEric for the only truly sensible (and correct) answer in this thread. Medal to you good sir.

17. theEric Group Title

Thank you! :)