Comme des milliers de personnes, recevez gratuitement chaque semaine [Maths]The early commuter.
Message de marie11 posté le 28-02-2007 à 00:23:52 (S | E | F | I)
Bonjour.
Voici un problème qui fait appel à votre bon sens et à votre perspicacité.
Réfléchissez et surtout évitez de vous lancer dans des calculs fastidieux,qui vous rebuteront très vite.
A commuter is in the habit of arriving at his suburban station each evening exactly at five(5) o'clock. His wife always meets the train and drives him home.
One day he takes an earlier train, arriving at the station at four(4). The weather is pleasant, so instead of telephoning home he starts walking along the route always taken by his wife. They meet somewhere on the way. He gets into the car and they drive home, arriving at their house ten (10) minutes earlier than usual. Assuming that the wife always drives at a constant speed, and that on this occasion she left just in time to meet the five (5) o'clock train, can you determine how long the husband walked before he was picked up ?
.
Correction : mardi 13 mars
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Modifié par bridg le 17-03-2007 15:47
transfert en maths
Message de marie11 posté le 28-02-2007 à 00:23:52 (S | E | F | I)
Bonjour.
Voici un problème qui fait appel à votre bon sens et à votre perspicacité.
Réfléchissez et surtout évitez de vous lancer dans des calculs fastidieux,qui vous rebuteront très vite.
A commuter is in the habit of arriving at his suburban station each evening exactly at five(5) o'clock. His wife always meets the train and drives him home.
One day he takes an earlier train, arriving at the station at four(4). The weather is pleasant, so instead of telephoning home he starts walking along the route always taken by his wife. They meet somewhere on the way. He gets into the car and they drive home, arriving at their house ten (10) minutes earlier than usual. Assuming that the wife always drives at a constant speed, and that on this occasion she left just in time to meet the five (5) o'clock train, can you determine how long the husband walked before he was picked up ?
.Correction : mardi 13 mars
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Modifié par bridg le 17-03-2007 15:47
transfert en maths
Réponse: [Maths]The early commuter. de TravisKidd, postée le 28-02-2007 à 06:48:29 (S | E)
Hello marie, I believe you mean 10 minutes earlier than usual, and correction 13 mars n'est-ce pas?
In order to arrive at home 10 minutes earlier, the wife would have had to pick him up at a certain point (let's call it A) 10 minutes earlier than the time when she would normally have passed A on the way home from the station. Those 10 minutes would have been spent driving from A to the station and back to A. Hence it would have taken 5 minutes for the woman to drive from A to the station. Therefore, she arrived at A (and picked her husband up) at 4:55. Therefore, her husband walked for 55 minutes before he was picked up.
Réponse: [Maths]The early commuter. de marie11, postée le 14-03-2007 à 09:20:10 (S | E)
Here is my answer.
Since they arrive home 10 minutes earlier than usual, this means that the wife has chopped 10 minutes from her usual travel time to and from the station, or 5 minutes from her travel time to the station. It follows that she met her husband 5 minutes before his usual pick-up time of five o'clock, or at 4:55. He started walking at 4, therefore he walked for 55 minutes.
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