Problema Solution
The octane rating of a gasoline is a measure of the amount of isooctane in a gallon of gas. Subaru recommends 91-octane for the 2008 Legacy 3.0 R. How much 87-octane gas and how much 93-octane should Kelsey mix in order to make 12 gal of91-octane gas for her Legacy?
Answer provided by our tutors
let 'x' represent the amount of 87-octane gas used, then '12-x' represents the amount of 93-octane gas used
0.91(12) = 0.87x + 0.93(12-x)
solving for 'x' we have x=4
12-4 = 8
Kelsey should mix 4 gallons of 87-octane gas with 8 gallons of 93-octane gas