One cell phone company charges $0.08 a minute per call. Another cell phone company charges $0.25 for the first minute and $0.05 a minute for each additional minute. At what point will the second phone company be cheaper?
The first company charges at a fixed rate.
The second company charges differently for the first minute and succeeding minutes
We want to know when will the charging of the second company be cheaper
Since the companies both charge on a per-minute basis, we should round-up our computed answer
Hence, the charging of the second company will be cheaper when the call duration exceeds 6 minutes (i.e. 7th minute).