Help I NEXI Multiple Choice Question 78 Sheffleld Corp. recently performed repair services for a customer that totaled $420. Somehow the bill was lost and the company accountant was trying to recreate the bill from memory. This is what was remembered Total bill $680 Labor profit margin s10 Materials profit margin 20% Total labor charges Cost of materials used $160 Total hourly cost $340 $22.50 How many hours were billed on the job? O 17.6 o 16.2 O 15.1 o 8.0 TOSH