1) We can write the following ratio for this, considering the ratios and the quantities:
a)
Notice that on the left side, the ratio gas/oil, and on the right side is the quantity of gas and the unknown quantity of oil.
So, so far we have 13/50 gallons of oil that must be mixed with gasoline.
b) For now, we need to convert that from gallons to fluid ounces so we can write out the following product:
So 13/50 or 0.26 gallons of oil. b) 33.28 fl oz.