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

### Instruction:
Peter and Kristin are to read 20 fantasy novels each in a week. Peter can read three times as fast as Kristin. If Peter reads one book in 18 hours, how long will Kristin read half of her books?

### Response:
 Kwa kuwa Peter anasoma mara tatu kwa kasi ya Kristin, Kristin atachukua masaa 18*3 = 54 kusoma kitabu kimoja.
Kristin anasoma nusu ya vitabu vyake, jumla ya vitabu 20/2 = <<20/2=10>>10.
Muda ambao Kristin atachukua kusoma nusu ya vitabu vyake ni 10*54 = <<10*54=540>>540.