please show what entries to add together to get the right answer. thanks

Using the following information determine the amount that Pearson will report as Cash and Cash Equivalents on the Balance Sheet at the end of December. Item Amount Cash is checking account $10,000 Petty cash 580 Postage Stamps 654 Check from customer dated Jan 20, next year 321 3-month certificate of deposit 35,000 12-month certificate of deposit 35,000 Check from customer dated Dec 15, this year 175 Undeposited Cashier's Checks from customer 729 IOU from customer 500 6-month U.S. Treasury bill purchased 4 months ago 2,500 2-month high-grade Canada government security purchased 1 month ago 1,000 Cash in savings account 100 Accounts Receivable 3,700 1-month U.S. Treasury bill purchased 2 weeks ago. 2,000 Time Deposits 1,600 Selected Answer. & A. 50,604 Answers: A. 50,604 B. 51,184