Answer:
The Journal entries are as follows:
(a) Accounts Receivable A/c Dr. $13,300
       To service revenue            $13,300
(To record the accounts receivable)
(b) Supplies A/c Dr. $2,000
     To Accounts Payable  $2,000
(To record the supplies on account)
(c) Rent Expense A/c Dr. $2,600
      To cash A/c            $2,600
(To record the rent paid)
(d) Cash A/c Dr. $10,300
    To Accounts Receivable $10,300
(To record the cash received from students)