30 miles per hour faster
We are given;
We are supposed to determine how fast the average speed would be if she made the trip in 5 hours.
Therefore, we can determine the speed when she took 5 hours
= 525 miles ÷ 5 hours
= 105 hours
Thus, the new speed would be 105 miles per hours
But, initial speed was 75 miles per hour
Therefore, she would travel 30 miles per hour faster to cover the journey in 5 hours.