It takes 8 hours to fill a tank with a particular chemical. Without treatment, all of the chemical in the tank would evaporate in 12 hours. If the tank is empty to start, and the chemical is not being treated as it enters the tank, how long will it take to have a full tank?

Question

mayankdevnani · Answer

24 hours
In this one the tank is filling at 1/3 the rate so will take 3 times as long to fill

mayankdevnani · Answer

ok     @stupidinmath

mayankdevnani · Answer

@mathslover       am i right?

mathslover · Answer

http://answers.yahoo.com/question/index?qid=20080108172709AAMgx5j Seems so :)

anonymous · Answer

this was my guess too.
thankyou so much @mayankdevnani  :D

mayankdevnani · Answer

oh!!!!!!!
@stupidinmath       very-very welcome

phi · Answer

this is a rate * time = distance  (but distance is 1 filled tank)

rate to fill is 1 tank per 8 hours  or 1/8
rate to empty is 1/12
the difference between filling and emptying is 1/8 - 1/12 = 1/24
now do
rate * time= 1 tank
1/24 * t =1
t= 24 hours

anonymous · Answer

Oh. Nice explanation, @phi . thanks also:)