Please explain because I am trying to understand the process

Jill Ardo, M.D., maintains the accounting records of Accardo Clinic on a cash basis. During 2020, Dr. Ardo collected $142,600 from her patients and paid $55,470 in expenses. At January 1, 2020, and December 31, 2020, she had accounts receivable, unearned service revenue, wages payable, and prepaid insurance as follows. (All long-lived assets are rented.) 1-Jan-20 31-Dec-20 $9,250 $15,927 2,840 4,111 Accounts receivable Unearned service revenue Wages Payable Prepaid Insurance 3,435 2,108 1,917 3,232 CASH BASED REVENUE (CBR) ACCRUAL BASED REVENUE (ABR) CASH BASED EXPENSE (CBE) ACCRUAL BASED EXPENSE (ABE) NET INCOME XYZ Company had cash receipts from customers in 2021 of $167,000. Cash payments for operating expenses were $122,000. XYZ has determined that at January 1, accounts receivable was $15,000, and prepaid expenses were $17,000. At December 31, accounts receivable was $18,600, and prepaid expenses were $25,200. Compute (a) service revenue and (b) operating expenses. Cash based revenue (CRB) Accrual based revenue (ABR) Cash based expense (CBE) Accrual based expense (ABE) Net Income