Jokes & Humor - Bicycle Brain Teaser

I heard this on NPR’s “Car Talk" but I did not hear the answer, so I only have my opinion. At first it sounded simple but the more I thought about it the more confused I got.

Bob and Joe have to get to town as quickly as possible. They have only one bicycle. Bob says “It would be quicker if we could each ride the bike part way so I’ll ride for a mile. Then I’ll leave the bike along the road, and when you get to it, you ride for a mile or so and leave it along the road. This way we’ll leapfrog each other and get to ride half way each. This will be quicker” Joe says “That won’t work. Think about it. Between the two of us someone will be walking every inch of the trip so it won’t be any faster your way.” Who is right?

Like I said, I don’t have the answer. I figured that we all could figure it out.

I worked this out using units of time and distance covered and reached the conclusion that Bob is correct.

Assumptions:

A walking speed of 3 MPH

A riding speed of 9 MPH

Bob rides for an hour and covers 9 miles. Joe walks those 9 miles and it takes him 3 hours. Joe reaches the bike that Bob left there 2 hours ago ( Bob has covered 6 miles before Joe got to the bike) and begins to ride they should both reach mile 18 in four hours.

Whereas, if they were to both just walk they would have only covered 12 miles in those 4 hours. Conversly,it would take six hours walking to cover those same 18 miles.

actually they would get there at the same speed as if they just walked it. why? because they have to wait for the walker to catch up. so pretty much they're walking the whole distance. (duh) :rolleyes:

actually it would take even longer than just waking. because now they have to get on and off the bike

In the two hours that the bike was left unattended, someone would pilfer it and they'd both half to walk all the rest of the way.

The best solution would be for Bob to give Joe a dink.

Not exactly. The first guy would leave the bike by the side of the road and start walking, leaving the bike for the other guy.

what's a dink

what's a dink
Good question!!

Must be an Australianism. It's when you give some a lift on your bike, either on the seat or on the handlebars. I sometimes dink my two boys from the gate to the shed when I get home. The two year old sits on the top tube holding onto the handlebars (and honking the horn), and the five year old sits on the rack. They love it.

We Australians and our strange names for things.

i always thought dink meant male genitalia or retarted person... man was i off :roflmao:

I worked this out using units of time and distance covered and reached the conclusion that Bob is correct.

Assumptions:

A walking speed of 3 MPH

A riding speed of 9 MPH

Bob rides for an hour and covers 9 miles. Joe walks those 9 miles and it takes him 3 hours. Joe reaches the bike that Bob left there 2 hours ago ( Bob has covered 6 miles before Joe got to the bike) and begins to ride they should both reach mile 18 in four hours.

Whereas, if they were to both just walk they would have only covered 12 miles in those 4 hours. Conversly,it would take six hours walking to cover those same 18 miles.I think that's right. Although it IS true that one or the other covers every inch of the distance the are times when both guys are walking at the same time but they are each covering a different part of the trip. They are in effect sharing the load - so it takes less time.

actually they would get there at the same speed as if they just walked it. why? because they have to wait for the walker to catch up. so pretty much they're walking the whole distance. (duh) :rolleyes:

actually it would take even longer than just waking. because now they have to get on and off the bike
That's exactly what I thought untill I figured it out on paper.