I just need the one answer for b with the work of how you got that answer

A partial adjusted trial balance of Sila Company at January 31, 2011, shows the following. Answer the following questions, assuming the year begins January 1. If the amount in Supplies Expense is the January 31 adjusting entry, and $500 of supplies was purchased in January, what was the balance in Supplies on January 1? $ If the amount in Insurance Expense is the January 31 adjusting entry, and the original insurance premium was for one year, what was the total premium and when was the policy purchased? Total preminum $ Purchase data If $3,500 of salaries was paid in January, what was the balance in Salaries Payable at December 31, 2010