Answer:
Split-off point:
The split-off point is the point at which products from the joint process appear and are identified.  The costs which are incurred up to the split-off point are called joint costs and the costs that are incurred after the split-off point are called as
Separable costs. Some joint products which emerge from joint process can be sold at the split-off point or some products can be put to further processing.
Compute the profit or loss from the three products as shown below'
Description                                                              A               B               C
Selling price after further processing                    20              13              32
Selling price at the split off point                            16               8        25
Incremental revenue per pound or gallon             4               5         7
Total quarterly output in pounds or gallons     $15,000    $20,000    $4,000
Total incremental revenue                              $60,000   $100,000  $28,000
Total incremental processing costs              $63,000   $80,000  $36,000
Total incremental profit or (loss)                       ($3,000)	$20,000  ($8,000)
Therefore the products A and C are need to be sold at the split off point and he product B should be processed further to earn good profits.