It looks like he pays 2.10/6 = $0.35 per additional minute, plus a single connection charge (which usually covers the first one or three minutes).
You don't need to know the connection charge to solve this.
30 minutes is an additional 20 beyond a 10 minute call, and would cost 20x0.35 = $7.00 more, or %11.75.
Solve the following word problem using a linear equation:
John has been recently looking at his phone bill. It costs $2.65 for a 4 minute call and $4.75 for a 10 minute call. How much will it cost John for a 30 minute call?
1 answer