Question

How many gallons of pure water should be evaporated from 160 gallons of a solution containing 12% salt so that the remaining solution contains 20% salt?

What are you being asked to find in this problem?

gallons of pure water

gallons of 12% salt solution

gallons of 20% salt solution

Answer 1

To find out how many gallons of pure water should be evaporated, we can use the concept of the conservation of mass. By setting up an equation with the given percentages and volumes, we can solve for the amount of water that needs to be evaporated.

Step-by-step explanation:

To find out how many gallons of pure water should be evaporated, we can use the concept of the conservation of mass. We'll start by assuming that there are x gallons of pure water that need to be evaporated. The amount of salt in the solution is given by the equation:

12% of 160 gallons = 20% of (160 - x) gallons

Simplifying the equation, we get:

0.12 * 160 = 0.20 * (160 - x)

After solving for x, we find that x is equal to 40 gallons. Therefore, 40 gallons of pure water should be evaporated from the solution.

Answer 2

The correct answer option is: 'gallons of pure water'.

Step-by-step explanation:

We are asked to find the number of gallons of pure water in this problem.

We know that the amount of salt that exists in the solution before the pure water is evaporated (0.12)(160) has to be equal to the amount of salt which is there after the evaporation takes place (0.20)(160-x).

Therefore, the number of gallons of pure water can be found using this equation:

(0.12) (160) = (0.20) (160-x)