A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 55% salt and Solution B is 80% salt. She wants to obtain 80 ounces of a mixture that is 75% salt. How many ounces of each solution should she use?

108 ounces

Step-by-step explanation:

Let x = the number of ounces of Solution A

Let y = the number of ounces of Solution B

Equation 1: x + y = 180      

Equation2: y = 180 - x

.60x+.85y=.75(180)

.60x+.85y=135      

Multiply both sides of the equation by 100 to remove the decimal points.

60x+85y=3500

60x+85(180 - x)=13500

60x+15300-85x=13500

-25x=-1800

x=72ounces

y=180-72

y=108 ounces          

1 1/4 hours

step-by-step explanation:

2/4 + 2/4 + 1/4 = 5/4 or 1 1/4