How SmaRT are You::The Famous Fly Puzzle

da_joker · 2012-05-29T09:25:37+00:00

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?.... 😨😁

How SmaRT are You::The Famous Fly Puzzle

da_joker

Member

Updated: Oct 26, 2024

Views: 958

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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Kaustubh Katdare

Administrator • May 29, 2012

In one hour with a speed of 15 mph, the fly should cover a total distance of 15 x 1 = 15 miles. ☕

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Anoop Kumar

Member • May 29, 2012

what if fly speed is 25mph😉

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Kaustubh Katdare

Administrator • May 29, 2012

ianoop
what if fly speed is 25mph😉
I'm not putting any more thought into this. Am I overlooking anything obvious? 😁

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da_joker

Member • May 30, 2012

Big_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.kasina

Member • May 30, 2012

i
da_joker
Big_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.

i tried by summing all the terms in the infinite series and ended up in total confusion and some decimal value,good thinking dude!👍

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Kaustubh Katdare

Administrator • May 30, 2012

Yeah, 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 Chowdary

Member • Jun 1, 2012

ya its very simple logic............it is 15miles.............and if the fly sped is 25mph then the ans is 25 miles..........👍

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Anoop Kumar

Member • Jun 1, 2012

Nope..if speed would be 25mph, then number of round taken by fly will be infinite.😀
since fly speed(25) > *bicycle relative speed (20).

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Sindhu Chowdary

Member • Jun 2, 2012

ianoop
Nope..if speed would be 25mph, then number of round taken by fly will be infinite.😀
since fly speed(25) > train relative speed (20).
it means if the speed of the fly is 30mph then also the rounds taken by it will be infinte??????
i am not able to understand the logic in your answer..........plz explain it...........

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Dilip jain

Member • Jun 3, 2012

ianoop
Nope..if speed would be 25mph, then number of round taken by fly will be infinite.😀
since fly speed(25) > *bicycle relative speed (20).
itz not infinite.....it is the speed .........coz the fly just flies as long as the bicycles meet

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Anoop Kumar

Member • Jun 3, 2012

Dilip jain
itz not infinite.....it is the speed .........coz the fly just flies as long as the bicycles meet
I think you are right... had solved this type of question long ago.. didn't remembered the process.
but definitely number of round will be infinite.

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Dilip jain

Member • Jun 3, 2012

hmm......i'll get back to u soonnnnn

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Sindhu Chowdary

Member • Jun 4, 2012

Dilip jain
itz not infinite.....it is the speed .........coz the fly just flies as long as the bicycles meet
i agree with u.....

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Dilip jain

Member • Jun 4, 2012

gwendollen
i agree with u.....
guys .........i can bet on it .....it is not "infinite"

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Vassilya

Member • Jun 10, 2012

There 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_joker

Member • Jun 13, 2012

guys 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_joker

Member • Jun 13, 2012

👍👍.......
😐

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Vassilya

Member • Jun 13, 2012

Yeye, we've established the answer, we're debating variations now 😀

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da_joker

Member • Jun 15, 2012

👍👍...

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