Answer:
25GB was used that month
Step-by-step explanation:
Here, we want to calculate the GB used for the month.
Since we have $59.99 for 20GB, then the extra that brought the bill to $75.99 must have been from the beyond charges.
The extra charges is thus $75.99 - $59.99 = $20
Now, since $4 is charged as extra and we have a total of $20, the number of extra GB is thus 20/4 = 5
So the total GB for that month is 20 + 5 = 25GB
