Question

Please help , I have no idea of how to do this

Answer 1

Hello!

The time difference between checkpoint 1 and checkpoint 2 is an hour and a half. 
At checkpoint A, the total amount of miles driven is 120. At checkpoint B, the total amount of miles driven is 195. 
To find the amount of miles driven between checkpoint 1 and 2, you will subtract the amount of miles at checkpoint 1 from checkpoint 2:
195-120= 75

The car drove 75 miles between 1:00pm to 2:30 pm. Because the total time between the checkpoints was an hour and a half, we can divide it by three (90 minutes total). We also need to divide the number of miles (75) by three to find an accurate answer. 
90/3=30
75/3=25

The car drove 25 minutes in half an hour. Now, one hour consists of 60 minutes, so we will multiply both calculations by 2 (for the total hour and the total amount of miles driven in the hour):
30x2=60
25x2=50

The car drove 50 miles per hour between checkpoints A and B. 

I hope this helps you! Have a great day!