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

### Instruction:
 Owen alizaliana kasa 21, na Johanna ana kasa 5 chini ya Owen. Baada ya mwezi mmoja, Owen ana kasa mara mbili ya hapo awali na Johanna anapoteza nusu ya kasa zake na kutoa zilizobaki kwa Owen. Owen alikuwa na kasa ngapi?


### Response:
 Johanna alikuwa na kasa 21 - 5 = <<21-5=16>>16.
Baada ya mwezi mmoja, Owen ana kasa 2 * 21 = <<2*21=42>>42.
Baada ya mwezi mmoja, Johanna ana kasa 1/2 * 16 = <<1/2*16=8>>8.
Baada ya mwezi mmoja, Owen ana kasa 42 + 8 = <<42+8=50>>50.