# Car Journey

THUDandBLUNDER
Posers and Puzzles 02 Apr '05 16:44
1. 02 Apr '05 16:444 edits
When a man drives his car from town A to town B he drives at 72mph downhill and at 56mph uphill.
Using the times taken for both legs of the journey, when he returned home he was able to calculate the distance between the two towns.

How fast does he drive on the flat?
2. The Plumber
Leak-Proof
02 Apr '05 21:19
Originally posted by THUDandBLUNDER
When a man drives his car from town A to town B he drives at 72mph downhill and at 56mph uphill.
Using the times taken for both legs of the journey, when he returned home he was able to calculate the distance between the two towns.

How fast does he drive on the flat?
I don't think it matters.
3. 02 Apr '05 21:43
By on the flat do you mean flat out as in 'full whack'? Must be 72mph in that case if that's what he is doing downhill.
Otherwise i think this question is very ambiguous and there is not enough information to find out half the answer.
4. Bowmann
Non-Subscriber
02 Apr '05 23:45
Originally posted by The Plumber
I don't think it matters.
What if it were 0mph?
5. 03 Apr '05 00:28
if it were zero, he wouldnt be able to get to his destination!
6. 03 Apr '05 01:141 edit
Originally posted by jimslyp69
By on the flat do you mean flat out as in 'full whack'? Must be 72mph in that case if that's what he is doing downhill.
Otherwise i think this question is very ambiguous and there is not enough information to find out half the answer.
Very ambiguous? Thank you very much!

I mean that there are three types of road: uphill, downhill, and flat.
Bu it is unknown how much of each there is.
7. Bowmann
Non-Subscriber
03 Apr '05 01:19
Originally posted by TDR1
if it were zero, he wouldnt be able to get to his destination!
He would...eventually.
8. 03 Apr '05 01:29
if he isnt moving how can he reach his destination?? explain that please.
9. The Plumber
Leak-Proof
03 Apr '05 02:53
Originally posted by Bowmann
What if it were 0mph?
It still wouldn't matter. As long as his speed is the same on the flat in both directions, the time spent on the flat is equal both coming and going and can be subtracted out of the total time for his calculating purposes.

If the speed on the flat is 0, then for him to have made the trip (as stated in the original problem), there would have to be no flat stretches in his journey.
10. ark13
Enola Straight
03 Apr '05 03:43
Originally posted by TDR1
if he isnt moving how can he reach his destination?? explain that please.
There's no explaination. He's just being stupid as usual.

I apoligise if you were being serious, but I don't see any way that could be true. If he were to ever reach his destination, his speed on the flat couldn't be zero unless there was no flats. And no, he wouldn't get there eventually traveling at speed zero.
11. 03 Apr '05 03:48
Originally posted by ark13
There's no explaination. He's just being stupid as usual.
He will probably claim that 'eventually' means after an infinite amount of time. ðŸ™„
12. 03 Apr '05 03:53
Originally posted by The Plumber
As long as his speed is the same on the flat in both directions, the time spent on the flat is equal both coming and going and can be subtracted out of the total time for his calculating purposes.
The times spent going uphill, downhill, and flat are non-zero but unknown.
We know only the uphill speed, downhill speed, and total time for each whole trip.
13. Alcra
Lazy Sod
03 Apr '05 06:53
Originally posted by THUDandBLUNDER
The times spent going uphill, downhill, and flat are non-zero but unknown.
We know only the uphill speed, downhill speed, and total time for each whole trip.
Actually, we only know two of the three.

We know only the uphill speed, downhill speed, and total time for each whole trip.

we do not know the 3rd point (bolded)
14. 03 Apr '05 07:004 edits
Originally posted by Alcra
we do not know the 3rd point (bolded)
Yeah, sorry, we don't know the total times.

But he knows!
And you know he knows.
And I know you know he knows.