How SmaRT are You::The Famous Fly Puzzle
Two bicyclists start twenty miles apart and head toward each other, each going at a steady rate of 10 mph. At the same time a fly that travels at a steady 15 mph starts from the front wheel of the southbound bicycle and flies to the front wheel of the northbound one, then turns around and flies to the front wheel of the southbound one again, and continues in this manner till he is crushed between the two front wheels. Question: what total distance did the fly cover?....
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Replies
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Kaustubh KatdareIn one hour with a speed of 15 mph, the fly should cover a total distance of 15 x 1 = 15 miles. โ
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Anoop Kumarwhat if fly speed is 25mph๐
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Kaustubh Katdare
I'm not putting any more thought into this. Am I overlooking anything obvious? ๐ianoopwhat if fly speed is 25mph๐ -
da_jokerBig_K is right here....
The slow way to find the answer is to calculate what distance the fly covers on the first,
northbound, leg of the trip, then on the second, southbound, leg, then on the third, etc., etc., and,
finally, to sum the infinite series so obtained. The quick way is to observe that the bicycles meet......
exactly one hour after their start, so that the fly had just an hour for his travels; the answer must therefore be 15 miles.
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akash.kasinai
i tried by summing all the terms in the infinite series and ended up in total confusion and some decimal value,good thinking dude!๐da_jokerBig_K is right here....
The slow way to find the answer is to calculate what distance the fly covers on the first,
northbound, leg of the trip, then on the second, southbound, leg, then on the third, etc., etc., and,
finally, to sum the infinite series so obtained. The quick way is to observe that the bicycles meet......
exactly one hour after their start, so that the fly had just an hour for his travels; the answer must therefore be 15 miles.
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Kaustubh KatdareYeah, used to happen to me all the time. We try to solve the easier problems the tougher way. Try this: #-Link-Snipped-#
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Sindhu Chowdaryya its very simple logic............it is 15miles.............and if the fly sped is 25mph then the ans is 25 miles..........๐
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Anoop KumarNope..if speed would be 25mph, then number of round taken by fly will be infinite.๐
since fly speed(25) > *bicycle relative speed (20). -
Sindhu Chowdary
it means if the speed of the fly is 30mph then also the rounds taken by it will be infinte??????ianoopNope..if speed would be 25mph, then number of round taken by fly will be infinite.๐
since fly speed(25) > train relative speed (20).
i am not able to understand the logic in your answer..........plz explain it........... -
Dilip jain
itz not infinite.....it is the speed .........coz the fly just flies as long as the bicycles meetianoopNope..if speed would be 25mph, then number of round taken by fly will be infinite.๐
since fly speed(25) > *bicycle relative speed (20). -
Anoop Kumar
I think you are right... had solved this type of question long ago.. didn't remembered the process.Dilip jainitz not infinite.....it is the speed .........coz the fly just flies as long as the bicycles meet
but definitely number of round will be infinite. -
Dilip jainhmm......i'll get back to u soonnnnn
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Sindhu Chowdary
i agree with u.....Dilip jainitz not infinite.....it is the speed .........coz the fly just flies as long as the bicycles meet -
Dilip jain
guys .........i can bet on it .....it is not "infinite"gwendolleni agree with u..... -
VassilyaThere is no way that I can see for an infinite loop unless the fly was superman and actually flew fast enough to turn back time...25 miles per hour for an hour would be 25 miles covered, excepting some really off the wall physics like surface curvature creating a difference between the distance flown and the actual distance of ground between marked axis of pivotal points.
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da_jokerguys it is not infinite....remember dey just have 1 hour to move..try to some the series together....u probably get 15.....
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da_joker๐๐.......
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VassilyaYeye, we've established the answer, we're debating variations now ๐
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da_joker๐๐...
You are reading an archived discussion.
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