Question

One canned juice drink is 20​% orange​ juice; another is 5​% orange juice. How many liters of each should be mixed together in order to get 15 L that is 10​% orange​ juice?

Answer 1

Let's call "x" and "y" the liters that we need:

x= liters in 20%
y=liters in 5%

Then, we have the following equations:

1) x+y=15
2) 20x/100+5y/100=(10/100)(15) ⇒ 0.2x+0.05y=1.5


We clear "x" from the equation 1):

1) x=15-y

Now, we substitute "x" into the equation 2) to find "y":

0.2x+0.05y=1.5
0.2(15-y)+0.05y=1.5
3-0.2y+0.05y=1.5
3-0.15y=1.5
y=10

Now, we can substitute y=10 into the equation 1) to find the value of "x":

x+y=15
x=15-10
x=5

How many liters of each should be mixed together in order to get 15 L that is 10​% orange​ juice?
5 liters of 20% orange​ juice and 10 liters of 5% orange juice