Debra King, D$.$D$.$S$.,$ opened a dental practice on January $1,2027.$ During the first month of operations, the following transactions

occurred.

$1.$ Performed services for patients who had dental plan insurance. At January $31,$ $$850$ of such services was completed but not

yet billed to the insurance companies.

$2.$ Utility expenses incurred but not paid prior to January $31$ totaled $$690$