A 400 g solution is 25% salt. How much salt must be added to produce a solution that is 40% salt?
To find out how much salt needs to be added, we can follow these steps:
Step 1: Calculate the amount of salt in the initial solution.
In a 400 g solution that is 25% salt, the amount of salt can be found by multiplying the total weight of the solution by the percentage of salt:
Amount of salt = 400 g * 0.25 = 100 g.
Step 2: Determine the desired total weight of the final solution.
Since we want to produce a solution with 40% salt, the total weight of the final solution needs to remain the same at 400 g.
Step 3: Calculate the amount of salt needed in the final solution.
To find out how much salt must be added, subtract the amount of salt already present in the initial solution from the amount of salt needed in the final solution:
Amount of salt needed = total weight of the final solution * desired percentage of salt - amount of salt in the initial solution
= 400 g * 0.40 - 100 g
= 160 g - 100 g
= 60 g.
Therefore, 60 grams of salt must be added to produce a solution that is 40% salt.