A researcher needs 60 L of 50% concentrate solution for a certain experiment, but she has only 30% solution and 70% solution. How many liters of the 30% and the 70% solutions should she mix to get what she needs?

30 liters of 30% solution and 30 liters of 70% of solution should be mixed by the researcher to get 60 liters of 50% solution.

Step-by-step explanation:

Let 'x' liters of 30% solution and 'y' liters of 70% solution are added together to get the required 60 liters of 50% of the solution.

According to the question, 30% solution and 70% solution are mixed and so, we get

Also, sum of the final solution should be 60 liters only so, we get

Solving equations (1) and (2), we get

Hence, we can say that 30 liters of 30% solution and 30 liters of 70% of solution should be mixed by the researcher to get 60 liters of 50% solution.

Link associated to

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step-by-step explanation: