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 16% orange juice

Answer 1

Answer:

11 L of 20% juice and 4 L of 5% juice

Step-by-step explanation:

Let

x L = amount of 20% juice

y L = amount of 5% juice

20% juice:

Amount = x L

Amount of juice $=0.2x$ L

5% juice:

Amount = y L

Amount of juice $=0.05y$ L

16% juice:

Amount = 15 L

Amount of juice $=0.16\cdot 15=2.4$ L

We mixed x L of 20% juice with y L of 5% juice to get 15 L of 16% juice, so

$x+y=15$

and

$0.2x+0.05y=2.4$

From the first equation:

$x=15-y$

Substitute it into the second equation:

$0.2(15-y)+0.05y=2.4\\ \\20(15-y)+5y=240\\ \\300-20y+5y=240\\ \\-20y+5y=240-300\\ \\-15y=-60\\ \\15y=60\\ \\y=4\ L\\ \\x=15-4=11\ L$