# Thread: problem involving guessing of jellybeans

1. ## problem involving guessing of jellybeans

A music store offers a prize to a customer who can guess the closest, the number of jelly beans that fill a litre jar on the counter. Estimate the number of jelly beans in the jar if 1 jelly bean is approximately 2 cm long (h) by 1.5 cm in diameter (d).
Volume = h x π x (d/2)2 (if you don’t have π on your calculator, use 3.1416 instead)
NB: 1 litre = 1000 cm
3,

i got
2cm x 3.1416 x (d/2)2 = 3.53 jelly beans

2. Originally Posted by vegito12
A music store offers a prize to a customer who can guess the closest, the number of jelly beans that fill a litre jar on the counter. Estimate the number of jelly beans in the jar if 1 jelly bean is approximately 2 cm long (h) by 1.5 cm in diameter (d).
Volume = h x π x (d/2)2 (if you don’t have π on your calculator, use 3.1416 instead)
NB: 1 litre = 1000 cm
3,

i got
2cm x 3.1416 x (d/2)2 = 3.53 jelly beans
Calculate (Volume of jar)/(Volume of jelly bean).

3. Well using common sense, a 1 litre jar will fit more than 3.53 jelly beans...

3.53 isn't the number of jellybeans, it is the volume of each average jellybean.
As mr fantastic said, use:

$\mbox{Number of Jellybeans} = \frac{\mbox{Volume of Jar}}{\mbox{Volume of each Jellybean}}$