The gas/oil ratio for a certain chainsaw is 20 to 1.

Question

a. How much oil (in gallons) should be mixed with 7 gallons of gasoline? b. If 1 gallon equals 128 fluid ounces, write the answer in fluid ounces. Mix ______ gallons of oil with 7 gallons of gas (simplify your answer)

Answer 1

Your proportion for gas to oil:

20 is to 1 as 7 is to x

 

20/1 = 7/x

20x = 7

x = 7/20 of a gallon of oil

 

(7/20 gal)(128 oz/gal) = 44.8 fl oz

 

Your last part is the answer from the first part:

Mix 7/20 gallons of oil with 7 gallons of gas