How many gallons of water and how many gallons of the premium antifreeze solution must be mixed?

Question

A chemical company mixes pure water with their premium antifreeze solution to create an inexpensive antifreeze mixture. The premium antifreeze solution contains 90%

 pure antifreeze. The company wants to obtain 180

 gallons of a mixture that contains 20%

 pure antifreeze. How many gallons of water and how many gallons of the premium antifreeze solution must be mixed?

Answer 1

premium contains 10% water

object is 180 L of 20% water

w represents the amount of water

0.10(180 - w) + 1.00w = 0.20(180)

Can you solve for w and answer?

Answer 2

Let x = number of gallons of 90% antifreeze to be added. Then 180 - x = number of gallons of water (which is 0% antifreeze)

0.90x + 0.00(180-x) = 0.20(180)

Solve for x.