A motorist travels 120 miles to his destionation at an average speed of 60 miles per hour and returns to the starting point at an average speed of 40 miles per hour.His average speed for the entire trip is
1. 53 miles per hour
2. 52 miles per hour
3. 50 miles per hour
4. 48 miles per hour
5. 45 miles per hour
total distance: 240 miles
total time: 120/60 + 120/40 = 2+3 = 5 hours
avg speed: 240/5 = 48 mph
4.6
Well, let's do some math to figure this out. On the way to the destination, the motorist travels 120 miles at 60 miles per hour, which takes him 2 hours. On the way back, the motorist travels the same 120 miles at 40 miles per hour, which takes him 3 hours. So, the total time for the round trip is 2 hours + 3 hours = 5 hours.
To find the average speed, we divide the total distance traveled (240 miles) by the total time taken (5 hours). So, the average speed for the entire trip is 240 miles / 5 hours = 48 miles per hour.
Therefore, the correct answer is 4. 48 miles per hour.
And remember, this motorist might not be the fastest driver, but at least they're consistent!
To find the average speed for the entire trip, we can use the formula:
Average speed = Total distance / Total time
Let's find the total distance first.
The motorist travels 120 miles to the destination and 120 miles back to the starting point, so the total distance is 120 + 120 = 240 miles.
Now, let's find the total time taken.
Time taken to travel to the destination = Distance / Speed = 120 / 60 = 2 hours
Time taken to return to the starting point = Distance / Speed = 120 / 40 = 3 hours
Total time taken = Time taken to travel to the destination + Time taken to return to the starting point = 2 + 3 = 5 hours
Now, let's use the formula to find the average speed:
Average speed = Total distance / Total time = 240 / 5 = 48 miles per hour
Therefore, the average speed for the entire trip is 48 miles per hour. So, the correct answer is option 4. 48 miles per hour.
To find the average speed for the entire trip, we can use the formula:
Average Speed = Total Distance / Total Time
Let's first find the total distance traveled for the entire trip. The motorist travels 120 miles to the destination and then returns to the starting point, so the total distance is twice the distance to the destination, which is 120 miles.
Total Distance = 2 * 120 miles = 240 miles
Now, we need to find the total time taken for the entire trip. We can calculate this by dividing the total distance by the average speed.
Time for the forward trip = Distance / Speed = 120 miles / 60 miles per hour = 2 hours
Time for the return trip = Distance / Speed = 120 miles / 40 miles per hour = 3 hours
Total Time = Time for the forward trip + Time for the return trip = 2 hours + 3 hours = 5 hours
Now we can calculate the average speed:
Average Speed = Total Distance / Total Time = 240 miles / 5 hours = 48 miles per hour
Therefore, the average speed for the entire trip is 48 miles per hour, which corresponds to option 4.