Santa Clara University Nakashima Gallery Petty Cash Accounting Worksheet

I’m working on a Accounting exercise and need an explanation to help me learn.

Assignment Instructions
Nakashima Gallery had the following petty cash transactions in February of the current year. Nakashima uses the perpetual system to account for merchandise inventory.
Feb 2
Write a $400 check to establish a petty cash fund.
Feb 5
Purchased paper for the copier for $14.15 that is immediately used.
Feb 9
Paid $32.50 shipping charges (transportation in) on merchandise purchased for resale, terms FOB shipping point. These costs are added to merchandise inventory.
Feb 12
Paid $7.95 postage to deliver a contract to a client
Feb 14
Reimbursed Adina Sharon, the manager, $68 for mileage on her car.
Feb 20
Purchased office paper for $67.77 that is immediately used.
Feb 23
Paid a courier $20 to deliver merchandise sold to a customer, terms FOB destination.
Feb 25
Paid $13.10 shipping charges (transportation in) on merchandise purchased for resale, terms FOB shipping point. These cost are added to merchandise inventory.
Feb 27
Paid $54 for postage expenses
Feb 28
The fund had $120.42 remaining in the petty cashbox. Sorted the petty cash receipts by accounts affected and exchanged them for a check to reimburse the fund for expenditures.
Feb 28
The petty cash fund amount is increased by $100 to a total of $500