Hey guys I'm new here, hoping to get to know you guys . Anyways i have this linear problem thats been doing my head in and there is no answer for it.

Hussein has just gained his real estate licence and is about to commence work for Hacking real estate agency. Hussein inquires about the cost of a mobile phone with two major phone companies optra and teltus.

Teltus has a billing system where the monthly cost can be middles by the equation Ct= 0.3x+15.

Optra believes that a majorit of customers make between 60 and 80 calls per month.

If optra charges a flat fee of $12 per month, how much should they charge per call (m) as to attract the majorit of customers ?

I got 0.3<m>0.3375 (m is bigger, not including 30, and smaller than, not including 0.3375. I don't know if I got the signs right). It can't be 0.3 otherwise it'll be cheaper no matter what and it can't be 0.3375 because it'll cost the same for 80 calls.

For some reason i dont think its right but it makes sense yeah? thank you