Nora leaves Town A and walks towards Town B at a speed of 100m/min. At the same time , Kate and Lixin walk from Town B towards Town A at a speed of 80mm/min and 75m/min respectively. If Nora meets Lixin 6 minutes after passing Kate, find the distance between Town A and Town B.
Please help me this one!! I need it now!! Thank you.
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----- what is written at this line and below it, is written/added by me, tutor @ikleyn -----
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I added it here, because the solution by tutor @MathTherapy is incorrect.
So, I simply copied-pasted the solution by @MathTherapy and pointed/commented
that place, which is incorrect.
<<<---=== this equation is INCORRECT (mine, @ikleyn's comment)
It is written (it is valid) under the assumption that only Nora is moving, while Kate stands unmoved; but it is not so. Therefore, everything that follows in the @MathTherapy post, is invalid.
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I know the tutor @MathTherapy as very accurate tutor at this forum.
Dear @Math Therapy, if you decide to take off your post, may be, it will be the best decision - I will not have any objections against it.
Because my greatest goal is to keep this forum as clean as possible (as I can).
By the way, my original (very old, ~ 10 years ago) solution to this problem
is the post number 1 in this bunch of posts.
So, had I place these my notes under my old solution, the chance would be great
that nobody sees it. It is why I placed my notes here . . .
You're right, @IKLEYN. I did the problem as though it had stated, "If Nora takes 6 mins
to GET to the POINT where Lixin was when Nora and Kate MET," instead of, "If Nora meets
Lixin 6 minutes after passing Kate........"
I EDITED the post, and REPOSTED the CORRECT solution!
Let time taken for Kate to meet Nora, and vice versa, be T
Since Nora left Town A and Kate and Lixin left Town B at the same time, distance Nora covered, when she met Kate = 100T
Also, distance Kate covered, when she met Nora, coming from Town B = 80T
When Nora and Kate met, both had covered the entire distance between Towns A & B
Therefore, distance between Towns A & B = 100T + 80T = 180T
At the same time that Nora and Kate met, Lixim, coming from Town B, had covered a distance of 75T
When Nora met Kate, Nora had traveled a distance of 100T. After meeting Kate, Nora then traveled an additional 6(100),
or 600 m for a total of 100T + 600 m, when she and Lixin met
Likewise, when Nora met Kate, Lixin had traveled a distance of 75T. 6 minutes thereafter, Lixin traveled an additional
6(75), or 450 m for a total of 75T + 450 m, when she and Nora met
Therefore, when Nora met Lixin, both had traveled a combined 100T + 600 + 75T + 450, the distance between the 2 towns
And, since the distance between the 2 towns is 180T, we get: 100T + 600 + 75T + 450 = 180T
175T + 1,050 = 180T
1,050 = 180T - 175T
1,050 = 5T
Time taken for Nora and Kate to meet/Lixim to cover 75T, or
mins
Thus, distance between Towns A & B = 180T, or 180(210) = 37,800 m