How would you find the exact number of pinto beans?

Question

Its in a glass container, and we cab weigh it

Answer 1

the only way to get the exact number is to count them.  You never know if the person who filled the jar with beans put something else inside to make it appear as if there are more beans inside.

Answer 2

Calculate the number of square inches in your container.  Calculate the number of beans in a square inch.  Multiply the number of square inches in the container times the number of beans in a square inch and you will come close - or just guess.

Answer 3

total weight - weight of jar = total weight of beans

total weight of beans/avg weight of bean = approx # of beans

Its not exact, but it'll get you close

Answer 4

I am assuming you can not take the beans out of the jar. If you can, then you can count them.

If not then....

1) Get an empty jar which is the same as the one being used and weight it.

2) Subtract the weight of the jar from the total weight of the pinto beans in the jar. (now you have the weight of the beans alone).

3) Take 10 pinto beans and weight them. Divide this weight by 10 to get the average weight of one pinto bean.

4) Divide the weight from part 2 with the weight of one pinto bean. Your answer will be the number of beans. It should be fairly accurate.

Answer 5

If you just want to do it mathematically by volume, here's what I would do.

(1) Estimate the volume of the glass container.

(2) Estimate the volume of one pinto bean.

(3) Take a guess at a mean volumetric packing effficiency. I would guess for a pinto bean it's going to be around 0.65 +/- 0.10, based on experience with similarly shaped objects.

(4) Multiply the packing efficiency by the glass container volume and divide by the pinto bean volume. There's your estimate.

If by weight, it's much simpler:

(1) Determine the weight of the empty glass container.

(2) Determine the average weight of a pinto bean (maybe weigh 10 beans and take the average)_

(3) Weight the full glass container, subtract the weight of the empty glass container, and divide by the average weight of the pinto bean.

These methods won't give you the exact number (the 2nd method is more accurate than the 1st, though), but it will get you close. Good luck!

Answer 6

Weigh a bean then the jar. That should give you a rough idea.