Question

Starting at home, Emily traveled uphill to the hardware store for 60 minutes at just 6 mph. She then traveled back home along the same path downhill at a speed of 12 mph. What is her average speed for the entire trip from home to the hardware store and back?

Answer 1

Its 8 mph and its not 24 mph

Answer 2

Answer:

8 mph

Step-by-step explanation:

Emily traveled uphill to the hardware store for 60 (1 hour) minutes at just 6 mph.

$Distance = Speed \times Time$

$Distance = 6 \times 1$

$Distance = 6 m$

She then traveled back home along the same path downhill at a speed of 12 mph.

So, on returning she traveled the same distance of 6 m.

So, time taken on returning = $\frac{Distance}{Speed}$

                                              = $\frac{6}{12}$

                                              = $\frac{1}{2}$    

So, average Speed= $\frac{Total Distance}{Total Time} =\frac{6+6}{1+\frac{1}{2}}$

                              = $=\frac{12}{\frac{3}{2}}$            

                              = $8$            

Thus her average speed for the entire trip from home to the hardware store and back is 8 mph.