Question

Starting at home, Ishaan travel uphill to the grocery store for 12 minutes at just 15 mph. He then traveled back home along the same path downhill at a speed of 30 mph. What is his average speed for the entire trip from home to the grocery store and back?

Answer 1

20 mph

Explanation:

Average speed is given as total distance traveled divided by total time taken:

S = d / t

Let us find the total distance traveled.

He traveled 12 minutes (0.2 hours) at a speed of 15 mph. The distance to the grocery store is therefore:

d = s * t

d = 15 * 0.2 = 3 miles

He travels the same distance to get back home, this means that his total distance traveled is 6 miles.

Let us calculate the time taken to get home from the grocery store:

t = d /s

t = 3 / 30 = 0.1 hour

Therefore, his total time is:

t = 0.2 + 0.1 = 0.3 hours

His average speed is therefore:

s = 6 / 0.3 = 20 mph