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.

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