Answer:
Pledges                      $600,000
Uncollectible Pledges at 15% Â Â Â Â -$90,000
Net Pledge Balance            $510,000
Pledges - 2017 at 60% Â Â Â Â Â Â Â Â Â Â $306,000
Unrestricted Net Asset - Contribution $306,000
  Account Titles                   Debit        Credit
a)Contribution Receivable           $360,000 Â
   Allowance for Uncollectible Pledges          $54,000
   Unrestricted Net Asset - Contribution          $306,000
b)Salary Expense (20 * 600) Â Â Â Â Â Â Â Â Â Â $12,000
Unrestricted Net Asset - Contribution          $12,000