Question

If Ying Zyiyu travels the first 200 miles of a trip going 50 mph and the last hundred going 4 mph, what was his average speed for the entire trip.

Answer 1

Answer: 10.34 mph

Explanation:

To calculate the average speed, we can use the formula:

Average speed = total distance / total time.

The total distance can be calculated by simply adding how many miles were traveled. 200 + 100 = 300 miles.

The total time can be calculated by calculating the time for each part of the trip with the formula:

Distance = speed * time. Solving for time we get:

Time = distance / speed.

For the first part of the trip, the time taken is:

Time = 200/50 = 4 hours

For the second part of the trip, the time taken is:

Time = 100/4 = 25 hours

Adding these times together, you get 29 hours.

Now going back to our regular formula:

Average speed = total distance / total time

Average speed = 300 / 29 = 10.34 mph

Answer 2

Time = Distance / Speed

For the first 200 miles traveled at 50 mph:

Time taken = 200 miles / 50 mph

Time taken = 4 hours

For the last 100 miles traveled at 4 mph:

Time taken = 100 miles / 4 mph

Time taken = 25 hours

Now, we can calculate the total time for the entire trip:

Total time = Time for the first portion + Time for the second portion

Total time = 4 hours + 25 hours

Total time = 29 hours

Finally, we can calculate the average speed:

Average speed = Total distance / Total time

Average speed = 300 miles / 29 hours

Rounding to two decimal places, the average speed for the entire trip is approximately 10.34 mph.