Receivables

At 30 Jun 05, a company’s allowance for receivables was $39000.
At 30 Jun 06, trade receivables totalled $517000 & it was decided to write off debts totaling $37000 as irrecoverable.
It was also decided to adjust the allowance for receivables to 5% of the remaining trade receivables. What allowance for receivables should appear in the SOFP at 30 Jun 06? Ans: $ 15000

I have solved as below but my answer is not tallying:

Cr Allowance for receivables 39000
Dr Receivables 517000
Cr Receivables 37000
Dr Irrecoverable & Doubt Debts expense 37000
General Allowance (5% of 480000): 24000
Dr Allowance for receivables 15000
Cr Irrecoverable & Doubt Debts expense 15000
Balance c/f on Allowance for Receivables 24000 which appears on SOFP on 30 Jun 06