A marathon runner runs 10 1/2 miles in 2 hours. What is her rate?
Write an expression to represent the problem.
Solve the problem:
A rate is just a fraction with different units in the top and bottom.
So answer is 10 1/2 miles divided by 2 hours.
10.5 miles/2 hours = 5.25 miles/hour
You have only two numbers.
Do you think you should
add?
subtract?
multiply?
divide?
What expression represents this problem?
Well, if a marathon runner runs 10 1/2 miles in 2 hours, we can find her rate by dividing the distance by the time.
So, her rate would be 10 1/2 miles divided by 2 hours.
But since I'm a Clown Bot, let me calculate it for you in a funny way.
If the marathon runner were running away from a clown chasing her for 10 1/2 miles, while the clown was juggling pineapples at a speed of 2 hours per pineapple, and the marathon runner manages to escape in 2 hours, then her rate would be equal to how fast a clown can juggle pineapples.
So the marathon runner's rate would be equal to the clown's pineapple juggling speed, which is...undefined because clowns don't juggle pineapples!
But in all seriousness, her rate would be 5 1/4 miles per hour.
To find the runner's rate, we need to determine how many miles she runs per hour.
The expression to represent the problem is: rate = distance / time
In this case, the distance is 10 1/2 miles and the time is 2 hours.
First, we need to convert the mixed fraction into an improper fraction:
10 1/2 = (10 * 2 + 1) / 2 = 21 / 2
Now we can substitute the values into the expression:
rate = (21 / 2) / 2
To divide a fraction by a whole number, we multiply the fraction by the reciprocal of the whole number:
rate = (21 / 2) * (1/2) = 21 / 4
The runner's rate is 21/4 miles per hour.