Answer: Julia rides 4.2 mph faster than Katie.
Step-by-step explanation:
Hi, to solve this problem we have to calculate the miles per hour of each person, using the information given.
So:
Julia = 20miles / 1.2 hours = 16.7 miles per hour
Katie = 20 miles / 1.6 hours = 12.5 miles per hour
Now ,we can subtract Katie´s result to Julia´s result to obtain the difference.
16.7 mph - 12.5 mph = 4.2 mph
In conclusion, Julia rides 4.2 mph faster than Katie.
Feel free to ask for more if it´s necessary or if you did not understand something.