How much oil to add to 20 gallons of gas for a boat motor that is 50 to 1 ratio?

To determine how much oil to add to 20 gallons of gas at a 50:1 ratio, you would divide the number of gallons of gas by the ratio. For 20 gallons, you would calculate 20 gallons ÷ 50 = 0.4 gallons of oil. Since there are 128 ounces in a gallon, this is equivalent to 0.4 x 128 = 51.2 ounces of oil. Therefore, you should add approximately 51.2 ounces of oil to 20 gallons of gas.