Problema Solution
A gas station owner has 30 gallons of gasoline worth $1.20 per gallon and some worth $1.40 per gallon. How many gallons of the $1.40 brand must the owner mix in to produce gasoline that costs $1.28 per gallon?
Answer provided by our tutors
1.20*30+1.40x=1.28(30+x)
36+1.40x=38.4+1.28x
1.40x-1.28x=38.4-36
.12x=2.4
x=2.4/.12
x=20 gal. of 1.40 gas is used.
Proof:
1.20*30+1.40*20=1.28(30+20)
36+28=1.28*50
64=64