### Brain Teasers

# Soda Bottle

You have a typical soda bottle, which is designed such that the bottom 3/4 is a perfect cylinder and the top 1/4 is an irregular shape. The bottle is filled about half way with soda. Using only a ruler, how can you determine exactly what percentage of the bottle's volume is filled?

### Answer

First measure the height of the liquid in the bottle with the bottle upright. Then, turn the bottle upside-down and measure the amount of space: the distance from the top of the liquid to the bottom of the bottle.You have now found the heights of liquid and air in terms of the cylinder only. You have essentially taken the irregular shape out of the equation. Simply divide the height of the liquid by the sum of the two heights to get the volume percent of the liquid in the bottle.

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## Comments

complex @.@;

-tangerine-

-tangerine-

I LIKE THAT,THOUGH I WOULD HAVE JUST DRANK THE SODA AND THEN I WOULD HAVE KNOW IT WAS EMPTY AND WOULDN'T HAVE TO BOTHER WITH THE MATH.

i think this should be under science......

I like this teaser. At first I thought there was a trick or a flaw, but then I realized you could get the difference by turning the bottle upside down. Very pleasing!

Good teaser. I thought of turning the bottle upside down but I kept forgetting that the liquid would not come up to the irregular bit when upright. I should have drawn it. I realised when I read the answer.

When I turned it upside down, all the liquid poured out. 0%

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