Miles IS TO gallons in one situation AS miles IS TO gallons in another situation. 84 miles IS TO 11 gallons AS 384 miles IS TO X gallons. 84 IS TO 11 AS 384 IS TO X IS TO means "OVER and "AS" means "EQUALS" 84 OVER 11 EQUALS 384 OVER XCross multiply: Divide both sides by 84 or about 50 gallons. Edwin