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

### Instruction:
For every 100 additional people that board a spaceship, its speed is halved. If the speed of the spaceship with 200 people on board is 500km per hour, what is its speed in km/hr when there are 400 people on board?

### Response:
 Kasi ya chombo cha anga hupunguzwa nusu kwa kila watu 100 wanaoongezwa mara ya kwanza, ikisababisha kasi ya 500/2 = <<500/2=250>>250km kwa saa kwa watu 300 waliomo ndani.
Kwa kuongeza watu wengine 100, kasi yake inapunguzwa nusu tena, ikisababisha kasi ya 250/2 = <<250/2=125>>125km kwa saa kwa watu 400 waliomo ndani.