Canoe riddle - no answer yet?!
Question: You can challenge yourself with close to 100 puzzles and riddles at http://www.mindchallenger.com You can go there if you can't figure out the answer. New questions are posted at the beginning of each month.
A guy is paddling a canoe up a stream at a constant speed (through the water). The water is flowing downstream at another constant speed (over ground). At some point a cooler falls out of the canoe into the water. After 10 minutes of paddling the guy notices that it is missing and turns around immediately and paddles downstream. While he is paddling downstream, he travels the same speed through the water as he did upstream. When he finally reaches the cooler, the cooler has traveled 1 kilometer from the spot where it fell out of the canoe.
How fast is the water flowing downstream (over ground) in kilometers per hour?
Answers: You can challenge yourself with close to 100 puzzles and riddles at http://www.mindchallenger.com You can go there if you can't figure out the answer. New questions are posted at the beginning of each month.
A guy is paddling a canoe up a stream at a constant speed (through the water). The water is flowing downstream at another constant speed (over ground). At some point a cooler falls out of the canoe into the water. After 10 minutes of paddling the guy notices that it is missing and turns around immediately and paddles downstream. While he is paddling downstream, he travels the same speed through the water as he did upstream. When he finally reaches the cooler, the cooler has traveled 1 kilometer from the spot where it fell out of the canoe.
How fast is the water flowing downstream (over ground) in kilometers per hour?
If you actually worked it out with some sort of complex formula (like I did the first time), then well done but there is an easier way.
Since the canoe is paddling through the same stream that their cooler is in, the speed of the water is not needed to figure out how long it takes them to catch the cooler. Since the canoe traveled away from it for 10 minutes, when it is turned around it will travel another 10 minutes back to it. Feel free to work it with different speeds of the water to see this.
So basically they retrieve the cooler from the water 20 minutes after it drops in (10 + 10 = 20). Since the cooler has traveled 1 kilometer in 20 minutes, the stream is traveling at 3 kph.
i don't know, this is confusing
6k ?
There is absolutely no way for me to figure that out
How can you work this out when we have no idea how long it took to get to the cooler.
All we know is he travelled for 10mins away from it(while it was moving downstream) then while he was going back it would be longer than 10mins(it was only 10mins to get back to spot where it fell out as he was going same speed) as it would still be going downstream while he was coming back! So he would have had to have travelled for longer than 20mins all up to catch up to the cooler.
Which means, for me anyway, that it is impossible to calculate the speed of the water without knowing how long it took for him to get to the cooler!
Hmmmm.