At the video rental shop, 5 movies can be rented for $6.99. Each additional movie rental is $1.99. What would be the total cost of renting 8 movies?

Question

I cannot figure out the answer. I found an answer but it is not marked.

Answer 1

   $6.99      for renting 5 movies

 + 1.99      for #6

 + 1.99      for #7

 + 1.99      for #8

---------

$12.96      for renting 8 movies