Answer:
The cost difference is $4.
Explanation:
Consider the provided information.
I am paying $60 a month for my service.
I would like to upgrade to the $80.00 service package because my new employer offers a 20% discount with your company.
If i get 20% of discount that means i need to pay only 80% of the original amount.
80% of 80 can be calculated as:
Therefore, now i need to pay $4 extra for the upgrade service.
Hence, the cost difference is $4.