Under her cell phone plan, Hannah pays a flat cost of $65.50 per month and $4 per
gigabyte, or part of a gigabyte. (For example, if she used 2.3 gigabytes, she would
have to pay for 3 whole gigabytes.) She wants to keep her bill under $70 per month.
What is the maximum whole number of gigabytes of data she can use while staying
within her budget?
