How much of a(n) 70% orange juice drink must be mixed with 14 gallons of a 20% orange juice drink to obtain a mixture that is 50% orange juice?

The amount of 70% orange juice drink is _____ gallons?

Question

How much of a(n) 70% orange juice drink must be mixed with 14 gallons of a 20% orange juice drink to obtain a mixture that is 50% orange juice?

The amount of 70% orange juice drink is _____ gallons?

nikato · Answer

have you tried?

anonymous · Answer

yes I have I tried to write out the problem but I was not sure if I was doing it right and I don't know how to put in the whole 14 gallon thing into the equation.

nikato · Answer

ok.
well.. with these kinda of problems, i like to make a table to make it easier

nikato · Answer

|dw:1410150161259:dw|

anonymous · Answer

I didn't know the 14 went to both.

nikato · Answer

|dw:1410150239323:dw|

miracrown · Answer

Assume we need x gallons of 70% orange juice drink.

The amount of pure orange when mixing them together is 70%*x+20%*14.
The total is x+14 gallons. 

So 70%*x+20%*14=50%*(x+14)

Solving that gives x=21 :) 
So we need 21 gallons of 70% orange drink.

nikato · Answer

you should be able to solve for x, which is the amount of 70% you need

and yes, the 14 went to both because the 20% is 14 gallons. and we said the 70% is x gallons.
so the mix would be the sum of that which is 14+x

anonymous · Answer

Oh alright thank you, and thanks for showing the table it made sense I figured out the answer.

nikato · Answer

no problem.
and yea, i just find it easier to solve these problems with the table. pretty helpful in organizing all those numbers