Answer:
a) 1/5 bucket = 1 gallon
b) 8.4 buckets = 1 barrel
c) 5376 fl oz per barrel
Explanation:
a) From the given information, 1 bucket = 5 gallons. This means 1/5 of a bucket is 1 gallon.
b) From the given information, 8.4 buckets = 1 barrel. This seems to be in the form that the question is asking for. If the question was asking how many barrels were in a bucket the answer would be 1/8.4 barrels = 1 bucket.
c) From the previously determined conversion factors, we can take ounces to barrels by converting barrels down to gallons.
1/8.4 barrels = 1 bucket; 1/5 bucket = 1 gallon; 1 gallon = 128 fluid ounces
We need to set up a series of fractions that use these factors:

These fractions can be simplified to

Multiply the fractions: 5376 fl oz per barrel
(Note that the units cancel out in the fractions so that only fluid ounces per barrel are left.)