### Brain Teasers

# Amoebas

Amoebas reproduce by splitting in two. An amoeba which does so every minute is placed in a jar at exactly ten o`clock in the morning. At 12:00 noon the jar is full. At what time is the jar half full?

### Answer

11:59. Since they double every minute, at 11:59 it was half full. One minute later it had doubled and was full.Hide Answer Show Answer

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## Comments

What hapens when that doubles and the jar explodes?

pretty easy, but I liked it

great

Amoebas are gross... Then again, if there's bad amoebas teasers, then I haven't heard it!

Man that's hard for indepth thinkers like me.

I was trying to work out a quadratic equation in my mind while reading that.

I was trying to work out a quadratic equation in my mind while reading that.

You know what....at first I was like....HOW BIG WAS THE JAR?!?!...

then i reread it......worked it backwards...finally got it...

LOVED IT DUDE!

then i reread it......worked it backwards...finally got it...

LOVED IT DUDE!

Actually the jar needs to be half full around 9:58 in the morning. Because.... if it not FULL of the bacteria on which the amoeba dine at ten, the time will quickly arrive when the amoebae reach constant mass. The only way to double in number will be halving the size of the individuals.

Great teaser. I had one just like this in math the other day, so that helped a lot.

You maybe should have put in the fact that each amoeba stays the same size as the ameoba it split from. Good teaser, nonetheless

But when would the jar be half empty?

Jim, half empty and half full are the same thing. Don't be daft.

I do think this should be a trick teaser though. It looks hard but is way too easy.

I do think this should be a trick teaser though. It looks hard but is way too easy.

Opps i dont mean that in a bad way FYI. =) easy teasers are good. they relieve stress. =O lol

A very old teaser, but still works!

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