a cell phone plan has a basic charge rs35 per month . the plan includes 400 free minutes and charge 10paise for each additional minute of usage. write the monthaly cost c as a function of number x of min used .
1 rs = ? paise
To find the monthly cost, let's break down the components:
1. Basic charge: The basic charge is given as Rs35 per month, which remains constant regardless of the number of minutes used.
2. Free minutes: The plan includes 400 free minutes. This means that if the number of minutes used (x) is less than or equal to 400, there will be no additional charges.
3. Additional minutes: If the number of minutes used (x) exceeds 400, there will be a charge of 10 paise (0.10 Rs) per minute for each additional minute.
Now, let's write the equation for the monthly cost (c) as a function of the number of minutes used (x):
- For x <= 400, there will be no additional charges, so the monthly cost is the basic charge: c(x) = Rs35.
- For x > 400, the monthly cost will include the basic charge plus the charges for additional minutes: c(x) = Rs35 + 0.10 Rs * (x - 400).
Therefore, the monthly cost (c) as a function of the number of minutes used (x) is:
c(x) =
Rs35 if x <= 400
Rs35 + 0.10 Rs * (x - 400) if x > 400