If someone could help me with it would be greatly appreciated. A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 60% salt and Solution B is 85% salt. She wants to obtain 40 ounces of a mixture that is 70% salt. How many ounces of each solution should she use?

16 for Sol A and 24 for Sol B

Step-by-step explanation:

Let x = the number of ounces of Solution A

Let y = the number of ounces of Solution B

x + y = 40        y = 40 - x

.60x + .85y = .75(40)

.60x + .85y = 30      Multiply both sides of the equation by 100 to remove the decimal points.

60x + 85y = 3000

60x + 85(40 - x) = 3000

60x + 3400 - 85x = 3000

-25x = -400

x = 16 ounces

y = 40 - 16

y = 24 ounces          

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: