A chemist is mixing 45% salt solution with a 30% salt solution to make 60 L of a new solution that will contain 40% salt. How much of each of the original solutions should the chemist use?

30 ml of 45% salt solution and 20 ml of 30% salt solution.

Step-by-step explanation:

Let x be the amount of 45% salt solution and y be the amount of 30% salt solution

the two equation will be:

x+y=60 -- A

0.45x+0.3y=0.4(60) -- B

Solve by substitution

Rewrite Equation A

x+y=60

x=60-y --- C

Substitute C into B

0.45(60-y)+0.3y=24

 27-0.45y+0.3y=24

                -0.15y=-3

                        y=20

Substitute the y=20 into equation C

x=60-20

x=30

Therefore, there was 30 ml of 45% salt solution and 20 ml of 30% salt solution.

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step-by-step explanation: