how many ounces of liquid a, which costs $3 per ounce, should be mixed with 12.6 ounces of liquid b, which costs $4 per ounce, to create a mixture which will cost $3.60 per ounce

Answer 1

3a + 4(12.6) = (12.6+a)(3.6)

3a +50.4 = 45.36 + 3.6a

.6a = 50.4 -45.36 = 5.04

a = 5.04/.6 = 8.4

a = 8.4 ounces of $3 liquid

mixed with 12.6 ounces of $4 liquid yields

to get 21 ounces of $3.60 per ounce

8.4(3) + 12.6(4) = 21(3.6)

25.2 + 50.4 + 75.6