# Average speed problem

• Aug 11th 2011, 09:48 PM
haftakhan
Average speed problem
A cyclist travels from Paris to the Louvre at an average speed of x km/h.
find the time taken in term of x ?

On his return journey from louvre to Paris, he decreases his average speed by 3 km/h.

Find the time taken in return journey in terms of x ?

if the difference between the times is one hour 20 minutes,

find the value of x ?
• Aug 11th 2011, 10:35 PM
Prove It
Re: Average speed problem
First of all, how far away is Paris from the Louvre?
• Aug 12th 2011, 06:10 AM
HallsofIvy
Re: Average speed problem
I was under the impression that the Louver was in Paris!
• Aug 12th 2011, 06:17 AM
Prove It
Re: Average speed problem
Quote:

Originally Posted by HallsofIvy
I was under the impression that the Louver was in Paris!

As was I, I just expected that the OP meant something like the distance between the Louvre to the centre of Paris...
• Aug 12th 2011, 07:05 AM
skeeter
Re: Average speed problem
let the distance = $d$

$x = \frac{d}{t_1} \implies t_1 = \frac{d}{x}$

$t_2 = \frac{d}{x-3}$

$t_1 - t_2 = \frac{d}{x} - \frac{d}{x-3} = \frac{4}{3}$

plug in $d$ (once you find out what it is) and solve for $x$