# How many Jellybeans are in the bottle

There are $n$ jellybeans in a bottle with unknown dimensions. What is the only surefire way of knowing how many jellybeans are in the bottle?

• +1, an easy question, but still might be interesting to the beginners. – Kenshin Nov 8 '14 at 13:45
• I've made a discussion about problem difficulty here: meta.puzzling.stackexchange.com/questions/1391/… – Kenshin Nov 8 '14 at 13:52
• Maybe this is lateral thinking? I mean, the only reason this wouldn't be immediately answered (and thus not really a puzzle) is because people try to ignore trivial answers. – TheRubberDuck Nov 8 '14 at 15:07
• These types of questions attract the dumbness in my brain, hahah DVL16 $\color{darkorange}{\bigstar}$ :P – Mr Pie Aug 29 '18 at 7:15

Perhaps by counting the number of jellybeans in the bottle.

• Alternative Answer: Eat them and say 0! – warspyking Nov 8 '14 at 13:49
• Could you place this as a spoiler? – warspyking Nov 8 '14 at 13:49
• @warspyking eating them all means 0 are in the bottle, 0!=1 isn't zero :P – libathos Nov 10 '14 at 14:52
• You'd better pour them out of the bottle first, otherwise you can only see the outer layer. – singletee Feb 9 '15 at 22:07

You can empty the bottle and count the jellybeans on the table.

• Why even bother counting them? If they're no longer in the bottle, the bottle contains zero jellybeans. – Simon Forsberg Nov 9 '14 at 0:46

There is another way that is probably far less time-consuming, depending on $n$.

Weigh the bottle of jellybeans. Call this value $F$.
Pour out the bottle of jellybeans.
Weigh the empty bottle. Call this value $E$.
Weigh a single jellybean. Call this value $J$.

The number of jellybeans is

$\frac{F-E}{J}$.

• You have no measure of the standard deviation of jelly bean mass this way. For a very large population, this will not produce a concrete answer. – Doresoom Jan 30 '15 at 16:18

Eat all of the jellybeans because jellybeans are yummy. There are 0 jellybeans in the bottle.