Answer:
18.75 is the answer
Step-by-step explanation:
since the internet usage is more than 4 hrs, the second equation will be used. that is
cost = (10 + 2.50 (x - 4)) where x is the usage hours.
thus
[tex]cost = 10 + (2.5 \times (7.5 - 4)) \\ = 10 + (2.5 \times 3.5) \\ = 10 + 8.75 \\ = 18.75[/tex]