SOLUTION: Jack runs at an average speed of 4 miles per hour for one hour.He then cycles 6 miles at 12 miles per hour.Find his average speed for the whole journey

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Question 843397: Jack runs at an average speed of 4 miles per hour for one hour.He then cycles 6 miles at 12 miles per hour.Find his average speed for the whole journey
Answer by fcabanski(1391) About Me  (Show Source):
You can put this solution on YOUR website!
Avg Speed is Distance/Time. You need to find the total distance traveled and the total time.


From the first part, you know Jack ran for 1 hour, and Jack ran 4 miles. 4 miles/hour * 1 hour = 4 miles.


The second part tells you how far Jack cycled. It's 6 hours. To find the time it took, use Distance = rate x time to find the time. Time = Distance/Rate = 6/12 = 1/2 hour.


Jack's total distance traveled is 4 + 6 = 10 miles. The total time is 1 + 1/2 hour = 3/2 hour.


The average speed is 10/(3/2) = 10 * 2/3 = 20/3 miles per hour = approximately 6.67 miles per hour.