Answer:
40 mph
Step-by-step explanation:
If the speed increased by 20%, now the speed is 120% of the original speed.
48 mph is 120%, so dividing by 6 will get 8 which is 20%.
If 8 is 20%, you can multiply it by 5 to get 40, which is 100%. This means 40 mph is the original speed.
Hope this helps!
