A man sold an article for $90, thus making a profit of 12.5%. What was the cost price of the article?

So a Man sold an article for $90 and made a 12.5% profit.
First what’s 10% of $90=$9
Second 1%of $90=$0.90
Third what’s 1/2 or 50% of $0.90=$0.45
Now
$9+$0.90+$0.90+$0.45=$11.25
$90+$11.25=$101.25

Answers:
Profit=$11.25
Price=$101.25