Final answer:
Genesis's rate over the last 8 hours is the distance she traveled in that time span (64 miles) divided by the time (8 hours), resulting in a rate of 8 miles per hour (mph).
Step-by-step explanation:
To determine Genesis's rate over the last 8 hours, we can use the information provided to calculate the distance she traveled during that time and then divide by the time to find her speed.
After 3 hours, Genesis is 26 miles from her house. After riding for 11 hours in total, she is 90 miles away. That means in the last 8 hours (11 hours - 3 hours), she has traveled the difference between 90 miles and 26 miles.
Let's calculate the distance travelled over the last 8 hours:
Distance = 90 miles - 26 miles = 64 miles
Now, to find the rate:
Rate = Distance / Time = 64 miles / 8 hours = 8 miles per hour (mph)
Therefore, Genesis's rate over the last 8 hours is 8 mph.