1. Prepare general journal entries on December 31, 2015 to record the following unrelated year-end adjustments.

a. On December 2, 2015, $6,200 of supplies were purchased and recorded as an asset. A count revealed $1,000 still on hand at December 31, 2015.

b. Services performed during December but not yet billed to customers totaled $5,000.

c. Depreciation of equipment is recorded using the straight-line method over 10 years. The equipment was purchased on December 1, 2015 for $300,000, and has no residual value at the end of its useful life.

d. Prepaid insurance expired during the month of December was $2,500.