What is 20% of 30 gallons of water

I need to take 20% of the water out of my 30 gallon fish tank. And replace with fresh water. I believe it is 6 gallons...I may have answered my own question but am not completely sure of it. Best answer get 10 easy points!

10% of 30 is 3, and 2 times that is 6. You were right!!!

U can do this 2 different ways:
Make an is over of sentence and make proportion: 20% OF 30 IS x.
20/100=x/30
Now you cross multiply and divide.
20•30=600
600-:-100= 6. Or u can do it a quicker way:
Turn 20% into a decimal and multiply it by the whole.
.2•30=6 now u can use this for future reference for finding percents of a fish tank.
So u were correct. 6gallons

Dear Tom,

First convert 20% to decimal that is move the decimal two places to the left and multiply!

Like this...
.20 times 30Gallons is equal to 6Gallons, your answer was correcta-mundo!
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http://www.youtube.com/watch?v=hdPa-djHb…

Per the video, you are trying to find "is" say what?
OK, OK...
is/of=%/100 the formula per video
So (is/30=20/100) your numbers
Cross multiply and divide...
So (30 times 20) divided by 100 is 6Gallons
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Yes, you're absolutely right.

20% = 20/100 = 1/5

(1/5)(30) = 30/5 = 6

Answer: 6 gallons

Check with other answers i am not a mathlete.
30/100=x/20
30(20)=100x
600=100x
600/100=x
x=6 gal

My mind works like this: 20% of 10 gal is 2 gal. There are 3 10 gal in 30 gal so 3x2 is 6. So 20% of 30 gal is 6 gal.

10% would be 3 gallons, so 20% would be 6 gallons. you are right. good job!

ya its 6 gallons.

ya i got the best answer thank you for your lawrel