Spongebob Problem

Eanaya

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Joined
Aug 22, 2012
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Down at Bikini Bottom, Spongebob is 90% water and weighs 10 ounces. On dry land, he is only 80% water. How much does Spongebob weigh now on dry land? Show your solution and also show why your solution does or doesn't make sense.

this is what I worked out, please let me know if I did something wrong...

if 90%=10
then 10%= 10/9
so 80%=90%-10%=10-1.1= 8.9oz
 
Down at Bikini Bottom, Spongebob is 90% water and weighs 10 ounces. On dry land, he is only 80% water. How much does Spongebob weigh now on dry land? Show your solution and also show why your solution does or doesn't make sense.

this is what I worked out, please let me know if I did something wrong...

if 90%=10
then 10%= 10/9
so 80%=90%-10%=10-1.1= 8.9oz
What you are writing is gibberish. 90% is NOT equal to 10! I suspect you meant that 90% of something was 10 but that is not correct either. If he weighs 10 ounces and is 90% water, then he contains 90% of 10 oz= 9 oz of water. That means that 10- 9= 1 oz is not water. That does not change on dry land. If we call his water weight, on dry land, "x" ounces, then his total weight is x+ 1 ounces and x is 80% of that: .8(x+ 1)= x. Solve that for x.
 
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