The phone company charges 10 cents to connect a call for one minute and 8 cents per minute after that. How long could you talk on the phone for 1 dollar?
The phone company charges 10 cents to connect a call for one minute and 8 cents per minute after that. We call x minute to talk after the first minute. We have 10+8x≤100 (cents) and 8x≤100-10 or 8x≤90 and x≤90:8 and x≤11.25 So: How long could you talk on the phone for 1 dollar: it is 11 minute and 15 seconds
