Under his cell phone plan, Joseph pays a flat cost of $48 per month and $3 per gigabyte, or part of a gigabyte. (For example, if he used 2.3 gigabytes, he would have
to pay for 3 whole gigabytes.) He wants to keep his bill under $55 per month. What is
the maximum whole number of gigabytes of data he can use while staying within his
budget?