CASH BUDGET< cash receipt from credit customers, irrecoverable debts

Credit sales: May (actual) $ 40,000 June (actual) $ 30,000 July (estimated) $ 25,000 recent debt collection experience: - current month's sales 20% - Prior month's sales 60% - Sales two months prior 10% - Cash discounts taken 5% - Irrecoverable debts 5% Q> why do we not take out the irrecoverable debt of 5%? Isn't this what cannot be considered to be received from the credit customer? Also do we not take out the cash discount as this would be a cash discount not a trade receivable discount? Thank you very much as always!