Please provide solution and explanation to this problem.

Besoluck company has sales of P480,000 and P450,000 for September and October respectively. Of the total Sales, 75% are on account. In addition, 1% of credit sales are returned and 20% of credit customers avail of a 2% discount. The company is able to collect 40% of credit sales in the month of sales and 60% is collected in the following month. During October, the company has written off P20,000 of worthless accounts but had collected P13,000 from an account previously written off. The company uses, 10% percent of receivables for estimating doubtful accounts. What amount is debited to doubtful accounts expense if the balance of the allowance for doubtful accounts on Oct 1 is P235050? * Your