Question

For his mobile phone service, John pays a monthly fee of $40 plus $15 for each 1 GB of data (rounded up) over his 8 GB of data that comes with his plan. For his monthly charge before taxes to be at most $70, how many gigabytes of data can he use in a month

Answer 1

Answer:

John can use no more than 2 GB of additional data

Step-by-step explanation:

Monthly fee = $40

Additional fee = $15 for each 1 GB of data (rounded up) over his 8 GB.

Let x be the number of additional data in GB over his 8 GB of data that comes with his plan.

Total monthly charge is

$C(x)=40+15x$

It is given that monthly charge before taxes to be at most $70.

$C(x)\leq 70$

$40+15x\leq 70$

$15x\leq 70-40$

$15x\leq 30$

Divide both sides by 2.

$x\leq 2$

Therefore, John can use no more than 2 GB of additional data.