Question

Starting at home, Jessica traveled uphill to the toy store for 12 minutes at just 10 mph. She then traveled back home along the same path downhill at a speed of 30 mph. What is her average speed for the entire trip from home to the toy store and back?

Answer 1

ok so the distance going to the toy store and back home is the same. So 12 minutes at just 10mph. That means the route is 12/60*10 miles long which is 2 miles long. Now it's 2 miles at a speed of 30mph. This means the time it will take is 4 minutes because 2/30*60=1/15*60=4. Now the total distance is 4 miles up and down and the total time is 16 minutes. So that means the answer is 15

Answer 2

The average speed is 15 mph

Explanation:

The average speed is not just the average of 10 mph and 30 mph.

She traveled for a longer time uphill (since she was going slower), so we can estimate that the average speed is closer to 110 mph than 30 mph.

To calculate the average speed, we will make use of the following:

`\text{average speed} = \frac{\blue{\text{total distance}}}{\pink{\text{total time}}}`

`\text{distance uphill} = \text{distance downhill}`

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