Devon sells clothes for cash from a market stall at 20% mark-up on cost. His opening inventory is valued at $27,500 and his closing inventory is valued at $15,000. His purchases during the year were $136,000. Devon can account for cash receipts of $145,000 but he thinks some may be missing. What is the amount of missing cash? O a. $18.200 O b. $33.200 O c. $3,500 O d. $40,625