A cell phone costs $20 for 400 minutes and $2 for each extra minute. Gina uses 408 minutes. How m

[math_celebrity]

A cell phone costs $20 for 400 minutes and $2 for each extra minute. Gina uses 408 minutes. How much will it cost?

Set up the cost function for minutes (m) if m is greater than or equal to 400
C(m) = 20 + 2(m - 400)

For m = 408, we have:
C(408) = 20 + 2(408 - 400)
C(408) = 20 + 2(8)
C(408) = 36