Brain Teasers
Couriers
A priest sent a courier from Rome to Venice to reach Venice in 7 days. At the same time, the Mayor of Venice sent a courier to Rome to reach Rome in 9 days. The distance was 250 miles. In how many days will they meet?
Hint
The speed of the couriers are 250/7 and 250/9Answer
The speed of the couriers are 250/7 and 250/9, so their approach speed was250(1/7 + 1/9) = 250 * 16/63 and they will meet in
63/16 = 3.94 days.
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Comments
umm...only a brainiac would know that answer.
hmmm, perhaps it is too early for me to get my head round this one.
only if i was in a thinking mood...im not sure id get this one tho..good post NEways
dont get mad or anything please, but i think you are way off on the answer.
In order to find the distance they meet you must equate both equations and find a common time for which they meet. for example-->r*t = r*t. You didnt even do that. I dont know what you did.
In order to find the distance they meet you must equate both equations and find a common time for which they meet. for example-->r*t = r*t. You didnt even do that. I dont know what you did.
oops, sorry, you are right. I just did it in a different way.
i just made 2 equations...........
T->in terms of days
1) [d = 250*(1/7) T].......
2) [250 - d = 250*(1/9) T].....
then i got 15750 = 4000T
......T = .25, then i multiplied that to each couriers days and added them up and it was close to your answer. 9(.25) + 7(.25) ==4. please tell me if im right or wrong on the way I worked it out.
i just made 2 equations...........
T->in terms of days
1) [d = 250*(1/7) T].......
2) [250 - d = 250*(1/9) T].....
then i got 15750 = 4000T
......T = .25, then i multiplied that to each couriers days and added them up and it was close to your answer. 9(.25) + 7(.25) ==4. please tell me if im right or wrong on the way I worked it out.
Just for specifics, it would be exactly 3.9375, though I am not disputing what you said.
The weird thing is, it doesn't make a lick of difference the difference between the two, so long as we have their times of travel. Just find the harmonic sum, and bingo!
That's pretty constant movement on the couriers' part. They must wear Depends or something.
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