Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2016-07-16 03:17:00

Mathegocart
Member
Registered: 2012-04-29
Posts: 2,226

Confirmation of bike problem

Kai rides his bike up the hill to school and back every day. If he travels twice as fast downhill as up, and it takes 30 minutes round trip how far away is it from his school?
I don't believe that there is a solution with the given information.


The integral of hope is reality.
May bobbym have a wonderful time in the pearly gates of heaven.
He will be sorely missed.

Offline

#2 2016-07-16 03:47:32

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Confirmation of bike problem

Hi;

I am going to say you are right. To get a number I need a bit more. You can solve it in terms of the variables of course.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#3 2016-07-16 19:54:10

Bob
Administrator
Registered: 2010-06-20
Posts: 10,053

Re: Confirmation of bike problem

hi Mathegocart

I tried this:

Let d be the distance one way and v be the velocity going up.  Let t be the time to go up and T be the time to go down.

Then

So t = 20 mins and T = 10 mins.

So d = 20v

That's as far as I can get.

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

Offline

#4 2016-07-16 20:09:14

thickhead
Member
Registered: 2016-04-16
Posts: 1,086

Re: Confirmation of bike problem

Without doing any calculation I can say he takes 10 minutes down the hill and 20 minutes for up the hill.


{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}
(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha
{Gods rejoice at those places where ladies are respected.}

Offline

Board footer

Powered by FluxBB