Peter R. answered 10/25/22
Experienced Instructor in Prealgebra, Algebra I and II, SAT/ACT Math.
The trick is to keep track of the ozs of sugar in the solutions.
2 oz. x 0.38 = 0.76 oz in the 2nd sol'n.
The resulting solution is 1 + 2 = 3 oz x .0.36 = 1.08 oz.
so there must have beed 1.08 - 0.76 = 0.32 oz in the unknown solution
0.32 oz sugar/1 oz sol'n = 32%
As an algebra solution it looks like 1x + 2(0.38) = 3(0.36)
x + 0.76 = 1.08
x = 0.32, or 32%
Check: 1(.32) = 0.32 oz sugar
2(0.36) = 0.76 oz sugar
1.08 oz sugar in 3 oz sol'n = 1.08/3 = 0.36 (36%)