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

### Instruction:
 John ananunua magazeti 500. Kila gazeti linauzwa kwa $2. Anauza 80% yao. Ananunua yote kwa bei ya 75% chini ya bei anayouza. Anapata faida kiasi gani?


### Response:
 Anauza 500*.8=<<500*.8=400>>400 magazeti
Anapata $400*2=$<<400*2=800>>800
Anaweza kununua kwa $2-1.5=$<<2-1.5=.5>>.5
Hivyo anapata punguzo la $500*.5=$<<500*.5=250>>250
Hivyo anatumia $500-250=$<<500-250=250>>250
Hii inamaanisha faida yake ilikuwa $800-250=$<<800-250=550>>550