It is given that 10 mL of fuel stabilizer treats 3 L of gasoline. Fuel stabilizer is added, in the specified concentration, to 30 liters of gasoline inside a tank to preserve it during storage. After some time has passed, 10 liters of gas is used up, and a fresh 10 liters of gas is pumped into the tank to replace it, but no additional stabilizer is added. After some additional time has passed, 15 liters of gas is used up and a fresh 15 liters of gas is pumped into the tank to replace it. How much stabilizer must now be added to the fuel inside the tank to maintain the correct concentration of stabilizer? Where appropriate, ignore the small volume contribution of the stabilizer in the calculations.
Answers
This is a nice variation on the usual density problems. It involves looking at the problem from the point of view of concentration. The initial amount of stabilizer in the tank is 100 mL. After 10 liters of gas is used up the first time, we have 20 liters remaining inside the tank. This corresponds to 2/3 of the fuel remaining, which also corresponds to 2/3 of the stabilizer remaining, which is 100×2/3 = 66.67 mL. Next, 10 liters of fresh gas is added, but no additional stabilizer is added, hence the amount of stabilizer remains at 66.67 mL (with 30 liters of gas now inside the tank). Next, 15 liters of gas is used up, which translates into 15 liters left in the tank, or 1/2 of the fuel remaining. This corresponds to 1/2 of the stabilizer remaining, which is 66.67×1/2 = 33.33 mL. We now add 15 liters of gas to the tank, bringing it back up to 30 liters, but with only 33.33 mL of stabilizer left. We know that for 30 liters of fuel we must add 100 mL of stabilizer. Hence, the amount of stabilizer to add is 100−33.33 = 66.67 mL.
Hope it will help you
Please mark me as brainliest