Phil is making a 40-kilometer canoe trip. If he travels at 30 kilometers per hour for the first 10 kilometers, and then at 15 kilometers per hour for the rest of the trip, how many minutes more will it take him then if he travels the entire trip at 20 kilometers per hour?
>he travels at 30 kilometers per hour for the first 10 kilometers
It takes 10/30 = 1/3 hour = 20 minutes
>at 15 kilometers per hour for the rest of the trip
The rest of the trip = 40-10=30km,
which takes 30/15=2 hours
So, in total the first option takes 2 hours and 20 minutes or 2 1/3 hours.
The second option:
>he travels the entire trip at 20 kilometers per hour
40/20=2 hours
>how many minutes more will it take
2 1/3 - 2 =1/3 hour = 20 minutes
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time = distance/speed
10/30 + 30/15 = 2 1/3
40/20 = 2
so, it takes 1/3 hour (20 minutes) more.
To find out how many minutes more it will take Phil, we'll need to calculate both scenarios and compare the times.
Let's start with the first scenario where Phil travels at 30 kilometers per hour for the first 10 kilometers and 15 kilometers per hour for the remaining distance.
For the first 10 kilometers, he will take:
Time = Distance / Speed = 10 km / 30 km/hr = 1/3 hour
For the remaining 30 kilometers, he will take:
Time = Distance / Speed = 30 km / 15 km/hr = 2 hours
So, the total time for the first scenario is:
Total Time = 1/3 hour + 2 hours = 2 1/3 hours
Now, let's calculate the second scenario where Phil travels the entire trip at a constant speed of 20 kilometers per hour.
For the entire 40 kilometers, he will take:
Time = Distance / Speed = 40 km / 20 km/hr = 2 hours
So, the total time for the second scenario is:
Total Time = 2 hours
To find out how many minutes more it will take in the first scenario compared to the second scenario, we'll need to calculate the difference:
Time difference = Total Time (Scenario 1) - Total Time (Scenario 2)
Time difference = (2 1/3 hours * 60 minutes/hour) - (2 hours * 60 minutes/hour)
Time difference = (140 minutes) - (120 minutes)
Time difference = 20 minutes
Therefore, it will take Phil 20 minutes more in the first scenario (traveling at 30 km/hr for the first 10 km and 15 km/hr for the rest) compared to the second scenario (traveling at a constant speed of 20 km/hr).