Answer:
The dog will run the 21-mile race in 4.04 hours
Step-by-step explanation:
The first thing we need to do is find out how far he ran the race at the local fair in 1 hour.
To do this, we can set up a simple relationship:
If he ran 10.5 miles in 2 hours,
He will run x miles in 1 hour
Cross multiplying, we have
x = (10.5 X 1)/2 = 5.25 miles in 1 hour.
We can now comfortably say that he runs at the rate of 5.2miles/hr
He now goes to the state fair race, which is 21 miles long.
if he runs at the rate of 5.2 miles in 1 hour,
He will run 21 miles in y hours
y = 21 / 5.2 = 4.04 hours
The dog will run the 21-mile race in 4.04 hours
