13/25 because I got the answer right
I think is
4x - 3 (-2) = 18
4x + 6 = 18
4x = 12
x = 3
25 * 16 = 400 tickets were sold
400 * $15 = $6000 was raised
Lets say, for ease, that the vat can hold a total of 70 gallons (or whatever you would like to use.) Use whatever number you want, I just picked this because it gives us a lot of clean numbers.
Now, if the inlet can fill it in 7 hours, that means that it is adding 10 gallons per hour. (70 gal/7 hours = 10 gal/hr)
For the outlet, use the same process, and you find that it drains the vat at 7 gallons per hour.
So, if you subtract the outlet from the inlet, you get 10 - 7 = 3 gallons per hour added.
Now just divide the size of the vat by that number, and you find your answer.
70 gallons / 3 gallons per hour = 23 1/3 hours.
10,000 x .10 = $1000
22500-10000=12500 x .12 = $1500
$1000 + $1500 = $2500
