__Set up the cost function C(r) where r is the number of room to design:__

C(r) = Cost per room * r + Site Visit Fee

C(r) = 55r + 100

__Now, the problem asks for an input of 6, which is__

*the number of rooms*. So we want C(6) which is the*cost to design 6 rooms*:C(6) = 55(6) + 100

C(6) = 330 + 100

C(6) =

**430**