Answer:
a) Corentine Co.
Cash paid to suppliers:
Beginning balance, September 30 $152,000
Purchases                                         $281,000
Ending balance, October 31            $132,500
Cash paid                                        $300,500
b) Valerian Co.
Sales to customers on account:
Ending balance, October 31              $89,000
Cash collected                                  $102,890
Beginning balance, September 30 $102,500
Sales                                                   $89,390
c) Alameda Company
Cash balance on September 30:
Cash disbursements $103,150
Balance, October 31   $18,600
Cash receipts           $102,500
Balance, Sept. 30       $19,200
Explanation:
The unknown amount for each case is the difference between the opening balance, the transactions for the month of October and closing balance.