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First, formula c(x) = 0.40x - 85 if x > 300 is INCORRECT in your post.
It should be c(x) = 35 + 0.40*(x-300) if x > 300.
Second, to the solution.
200 minutes is in the domain [0,300 minutes].
THEREFORE, apply FIRST formula c(200) = 35 dollars. ANSWER
Solved and thoroughly explained.