The total monthly charges, $C, for a mobile plan consist of a fixed amount of $ 120 and a variable amount which depends on the usage. For every minute used, $0.20 is charged. If the duration of usage is 120 minutes, calculate the total monthly charges for the mobile plan

The total monthly charges C for a mobile plan consist of a fixed amount of 120 and a variable amount which depends on the usage For every minute used 020 is cha class=