=+A10-3 Classifying costs Time technician arrived at 2:00 p.m. to begin work. By 4:00 p.m. the problem was diagnosed as a failed circuit board. Unfortunately, the technician did not have a new circuit board in the truck, since the technician’s previous customer had the same problem, and a board was used on that visit. Replacement boards were available back at the On-Time shop. Therefore, the technician drove back to the shop to retrieve a replacement board. From 4:00 to 5:00 p.m., the On-Time technician drove the round trip to retrieve the replacement board from the shop.

At 5:00 p.m. the technician was back on the job at Laurie’s home. The replacement pro¬

cedure is somewhat complex, since a variety oftests must be performed once the board is installed. The job was completed at 6:00 p.m.

Laurie’s repair bill showed the following:

Circuit board $ 80 Labor charges 190 Total $270 Laurie was surprised at the size ofthe bill and asked for some greater detail supporting the calculations. On-Time responded with the following explanations:

Cost of materials: