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

### Instruction:
Matilda bought a smartphone for $300. Then she decided she wouldn't use it anyway and sold it for $255. What percentage of the initial cost did she lose?

### Response:
 Tofauti kati ya gharama ya awali na kiasi alichouza simu ni $300-$255 = $<<300-255=45>>45
$45 ni (($45/$300)*100)=<<45/300*100=15>>15% ya $300