Answer:
≈ 11 ounces
Step-by-step explanation:
(This is the easiest method I can explain, there is probably a simpler one)
We can make a system of equations (x = oz. of pure oil, y = oz. of mixture):
x + y = 100 oz. -> y = 100 - x
x + 0.0451y = 0.15(100) -> x + 0.0451y = 15
Using substitution, we get that x + 0.0451(100 - x) = 15.
This is equal to x + 4.51 - 0.0451x = 15.
Subtracting both sides by 4.51 and combining like terms gets us
0.9549x = 10.49.
Dividing both sides gives us about 11 ounces.
