Change the 15 1/3 to an improper fraction (46/3). Next multiply this by (3/4).
(46/3)(3/4) = 46/4 = 23/2 = 11.5 gallons was used to water the plants
15 1/3 - 11 1/2 = 46/3 - 23/2 = 92/6 - 69/6 = 23/6 = 3 5/6 gallons of water are left in the barrel
Im pretty sure the answer is 2x^3-x^2+13x-6/x-3
Total = 36oz
Amount of 18% solution = x
Amount of 9% solution = 36 - x
Using the fact that (amount of solution) * (percent HCl) = amount HCl we can set up an expression for the amount HCl in a mixture of 18% and 9% solutions with a total volume of 36oz.
Amount of HCl = x*0.18 + (36 - x)*0.09
If we divide this by the amount of solution we get percent HCl, and we have a target of 10% HCl. Now we have an equation to solve,
[x*0.18 + (36 - x)*0.09]/36 = 0.1
x*0.09 + 3.24 = 3.6
.09x = 0.36
x = 4
Therefore,
4 ounces of 18% HCl solution and 32 ounces of 9% HCl solution
Check:
[(4*.18) + (.09*32)]/36 = 0.1?
0.1 = 0.1 Yes.
You will need to run around 10 times because 3000m is 3km and 300*10 is 3000 :) i hope i helped