Question

A scientist needs 120 mL of a 20% acid solution for an experiment the lab has available 25% and a 10% solution how many milliliters of a 25% solution how many milliliters of the 10% solution should scientist make to the 20% solution ?

Answer 1

What the person said above

Answer 2

Explanation:

Let x be the number of milliliters of 25% solution needed, and y be the number of milliliters of 10% solution needed. Then we have two equations:

x + y = 120 (the total volume of the solution)

0.25x + 0.1y = 0.2(120) (the amount of acid in the final solution)

Simplifying the second equation, we get:

0.25x + 0.1y = 24

Multiplying both sides of the first equation by 0.1 and subtracting from the second equation, we get:

0.15x = 12

Solving for x, we get:

x = 80

Substituting this value back into the first equation, we get:

80 + y = 120

Solving for y, we get:

y = 40

Therefore, the scientist needs to mix 80 mL of 25% solution and 40 mL of 10% solution to make 120 mL of 20% solution.