Sue rides her bike at a rate of 15 mph to May’s house 5 miles away. Then Sue and May walk to
a park 2 miles away at a rate of 3 mph. What was Sue’s average speed for the entire trip?
Sue's time riding the bike = 5/15 hrs = 1/3 hr
Sue's time walking the 2 miles = 2/3 hr
total time = 2/3 + 1/3 = 1 hr
total distance = 7 miles
average speed = 7/1 = 7 mph
Sue's time riding the bike = 5/15 hrs = 1/3 hr
Sue's time walking the 2 miles = 2/3 hr
total time = 2/3 + 1/3 = 1 hr
total distance = 7 miles
average speed = 7/1 = 7 mph
To find Sue's average speed for the entire trip, we need to calculate the total time it took her to travel the entire distance and then divide it by the total distance.
1. Calculate the time it took Sue to ride her bike to May's house:
Distance = 5 miles
Speed = 15 mph
Time = Distance / Speed
= 5 miles / 15 mph
= 1/3 hour
2. Calculate the time it took Sue and May to walk to the park:
Distance = 2 miles
Combined speed = 15 mph (Sue's biking speed) + 3 mph (walking speed) = 18 mph
Time = Distance / Combined speed
= 2 miles / 18 mph
= 1/9 hour
3. Calculate the total time for the entire trip:
Total time = Time biking + Time walking
= 1/3 hour + 1/9 hour
= 4/9 hour
4. Calculate the total distance for the entire trip:
Total distance = Distance biking + Distance walking
= 5 miles + 2 miles
= 7 miles
5. Calculate the average speed for the entire trip:
Average speed = Total distance / Total time
= 7 miles / (4/9) hour
= 7 miles * (9/4) hour
= 63/4 mph
= 15.75 mph
Therefore, Sue's average speed for the entire trip was 15.75 mph.
To find Sue's average speed for the entire trip, we need to calculate the total time she spent on the trip and divide it by the total distance covered.
First, let's calculate the time Sue took to ride her bike to May's house. We can use the formula: Time = Distance / Rate.
Distance to May's house = 5 miles
Rate of riding her bike = 15 mph
Time taken to ride to May's house = 5 miles / 15 mph = 1/3 hour (or 20 minutes)
Next, let's calculate the time Sue and May took to walk to the park. Again, we can use the formula: Time = Distance / Rate.
Distance to the park = 2 miles
Rate of walking = 3 mph
Time taken to walk to the park = 2 miles / 3 mph = 2/3 hours (or 40 minutes)
Now, let's calculate the total time for the entire trip by adding the time for riding her bike and the time for walking to the park.
Total time for the trip = Time taken to ride to May's house + Time taken to walk to the park
= 1/3 hour + 2/3 hours
= 1 hour
Finally, let's calculate the average speed by dividing the total distance covered by the total time taken.
Total distance covered = Distance to May's house + Distance to the park
= 5 miles + 2 miles
= 7 miles
Average speed = Total distance covered / Total time for the trip
= 7 miles / 1 hour
= 7 mph
Therefore, Sue's average speed for the entire trip is 7 mph.