Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
Mark spent 220 dollars to fix his car.  It needed two parts that cost 20 dollars each, and labor cost .5 dollars a minute. How many hours did the mechanic work?

### Response:
 Gharama ya kazi ni dola 0.5 * 60 = <<.5*60=30>>30 kwa saa
20 + 20 = $<<20+20=40>>40 kwa vipuri
220 - 40 = $<<220-40=180>>180 kwa kazi
180 / 30 = <<180/30=6>>6 masaa