Answer:
The journal entries are as follows:
(i) On March 31,
Finished Goods A/c Dr. $56,400
      To Work in Process     $56,400
(To record the completion of the two jobs)
(ii) On March 31,
Cash A/c Dr. $38,000
 To sales           $38,000
(To record the sale Job 10)
(iii) On March 31,
Cost of goods sold A/c Dr. $21,400
      To finished goods         $21,400
(To record the cost of the job sold)