Sandhill Company had cash receipts from customers in 2020 of $117,140. Cash payments for operating expenses were $104,320. Sandhill has determined that at January 1, accounts receivable was $14,620, and prepaid expenses were $20,400. At December 31, accounts receivable was $15,400, and prepaid expenses were $26,610. Compute (a) service revenue and (b) operating expenses.