To arrive at 2000 liters of 60% saline solution the attendant has to mix a 90% and a 40% saline solution. How many liters of each should be used?

800 liters of 90% saline solution and 1200 liters of 40% saline solution should be used.

Step-by-step explanation:

Given:

At 2000 liters of 60% saline solution the attendant has to mix a 90% and a 40% saline solution.

Now, to find the number of liters of saline solution each should be used.

Let the liters of 90% saline solution mix be

And let the liters of 40% saline solution mix be

So, the total number of liters:

Now, the total percentage of saline solution:

Substituting the value of from equation (1) we get:

Subtracting both sides by 800 we get:

Dividing both sides by 0.5 we get:

The liters of 90% saline solution mix = 800.

Now, substituting the value of in equation (1) to get the liters of 40% saline solution:

Thus, the liters of 40% saline solution = 1200.

Therefore, 800 liters of 90% saline solution and 1200 liters of 40% saline solution should be used.

typically if you want , you would actually put questions here for us to you. but hey, that's just me. maybe someone will magically answer the questions for you without knowing what they are.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.