Question

A solution contains 7% salt. How much water should be added to 70 ounces of this solution to make a 4.9% solution?

Answer 1

Answer: 30 Oz of water should be added

Step-by-step explanation: Since 7% of the original solution is salt,

→ (.07)(70) = 4.9 Oz of salt.

 

Let the amount of water being added be W.

Then there will be

(70 + W) oz of solution, but still with 4.9 oz of salt.

 

Since we want the new solution to be 4.9% salt, we write:

.049 * (70 + W) = 4.9

→ 70 + W = 100 (by dividing both sides by .049),

→ W = 30 oz (by subtracting 70 from both sides), So the answer should be 30 Oz