 
 <prompt> Matilda buy smartphone for $300. She come decide say she no go use am again and sell am for $255. Wetin be the percentage of the initial cost wey she lose? <response>: ```Di difference between di initial cost and di amount wey she sell di phone for na $300-$255 = $45
$45 na (($45/$300)*100)% = 15% of $300

Di final answer: 15.``` 