Question

How many liters each of a 10 % acid solution and a 80 % acid solution must be used to produce 70 liters of a 65 %acid solution? (Round to two decimal places if necessary.)

Answer 1

Answer:

15 liters of the 10% acid solution must be used

55 liters of the 80% acid solution must be used

Step-by-step explanation:

Let the volume of the 10% acid solution be x

Let the volume of the 80% acid solution be y

The combination of the two solutions gives 70 liters

x + y = 70..............................(1)

The 70 liters solution is equivalent to 65%

10x + 80y = 70(65)

10x + 80y = 4550..........................(2)

Make x the subject of the formula in equation (1)

x = 70 - y...............................(3)

Substitute equation (3) into equation (2)

10(70 - y) + 80y = 4550

700 - 10y + 80y = 4550

70y = 4550 - 700

70y = 3850

y = 3850/70

y = 55 liters

Substitute y = 55 into equation (3)

x = 70 - 55

x = 15 liters