Answer:
His new time compared to the old time was twice as much.
Explanation:
Consider the provided information.
The distance covered in first trip is 50 miles.
The distance covered in later trip is 300 miles.
The relation between speed, time and distance is:

Let speed of the first trip is x.
Thus, the speed of the later trip is 3x.
Now use the above formula by substituting distance 50 and speed as x.

Similarly, time taken in second trip is:

Now, Compare new time with old.



Therefore, his new time compared to the old time was twice as much.