I added a screenshot of the original question.
Now, first we will need to calculate the speed of each truck and then get the time that each of them will take to travel the 225 miles.
The basic rule that we will use for this question is:
velocity = distance / time
Part (a): getting the velocity of each truck:
For the large truck:
We are given that the truck took 4 hours to travel 180 miles. Therefore:
velocity of large truck = 180 / 4 = 45 miles/hour
For the small truck:
We are given that the truck took 3 hours to travel the same 180 miles. Therefore:
velocity of small truck = 180 / 3 = 60 miles/hour
Part (b): getting the time required for each truck to travel 225 miles:
For the large truck:
We have the distance = 225 miles and the velocity = 45 miles/hour. Therefore:
velocity = distance / time
time = distance / velocity = 225 / 45 = 5 hours
For the small truck:
We have the distance = 225 miles and the velocity = 60 miles/hour. Therefore:
velocity = distance / time
time = distance / velocity = 225 / 60 = 3.75 hours