Schedule of Cash Collections of Accounts Receivable

Office World Inc. has "cash and carry" customers and credit customers. Office World estimates that 20% of monthly sales are to cash customers, while the remaining sales are to credit customers. Of the credit customers, 25% pay their accounts in the month of sale, while the remaining 75% pay their accounts in the month following the month of sale. Projected sales for the next three months of 2014 are as follows:

August: $126,000 September: $158,000 October: $231,000

The Accounts Receivable balance on July 31 2014 was $84,000

Can I get any help on this? Thanks!!!!!