The same answer 81/95 can be found using two different methods. Please view the attachments below.
<h2>
Explanation:</h2><h2>
</h2>
In this problem, we know that Harry saved $100 each week for 8 weeks. In other words, he saved a total amount of money:

We know that he earned $48 on his savings of $800, so for every $100 the interest (I) he earns is:

So, in conclusion Harry did earn $6 in interest for every $100