Answer:
He needs to pay $8.75 as a service cost.
Explanation:
Consider the provided information.
Peter signed up for a program that Cost $10.50 per month to stream movies to his computer decided to cancel his service after 5/6 month.
He only has to pay for the amount of time he used the service.
Now we need to find how much his service cost.
If he used 5/6 month that means he needs to pay 5/6th part of $10.50
This can be written as:

Hence, he needs to pay $8.75 as a service cost.