A lifelog of a well-travelled single parent who had a life extension in 2000, blogs indiscriminately about her journey through life fulfilling unfinished business and promises that will soon complete her existence...

::College Algebra

Tuesday, September 28, 2004

My daughter sought my assistance in her College Algebra homework. If you know the solution to this motion problem, I will appreciate it. I have less than eight hours to find out the answer. I was good in Algebra before, but my memory isn't working well...

Anyone?

Distance = (rate)(time), or d = rt

From this equation we can derive the associated relationships:

r = d / t , t = d / r

PROBLEM: Two men are 10 mi apart. If they start walking at noon on one straight road at the rate of 3 km/hr and 2 km/hr, find the time they will be 2 miles apart.

ANSWER: 1:36PM, 2:24PM

My daughter wanted me to provide the solution but my mind and memory are not working... can you help?


Posted on September 28, 2004 11:33 PM TrackBack


butterfly Let me know you were here, your thoughts are welcome!

Just to let the people know, both my daughter and I had difficulty finding the solution to the given problem and answer because the book has typographical errors. Miles should be in kilometers and here's how my daughter got the solution:

Let X be the time covered for them to be 2 km apart.

IN DIAGRAM:
.............RATE......TIME......DISTANCE
Man 1..3km/hr.........X................3X........
Man 2..2km/hr.........X................2X........

EQUATION 1:
3X + 2X = 10 - 2
........5X = 8
... ......X = 8 / 5 or 1.6 or 1:36 HRS

EQUATION 2:
3X + 2X = 10 + 2
........5X = 12
..........X = 12 / 5 or 2.4 or 2:24 HRS

Thank you for those who tried to get the solution for us. I appreciate it...


Posted by: Laila* on October 6, 2004 03:27 PM

There is no problem in the quiz, yes the student should conevrt miles to Km based on 1 mile = 1.6Km and accordingly solve the problem.
my solution for this problem will be as follows:
D1+D2+D3=16Km, where D1 is the distance the first travelr cross before reaching the enquired point, 3.2Km apart, D2 is the distance the second travler cross before reaching his point from his side, where D3 is 3.2Km. converting D=R*T and
based on the fact that at the specific point time will be equal the time will be required is 2.56hrs making the final results is 12+2.56 = 14h 33 mnt


Posted by: iiudm on September 30, 2004 03:25 AM

We concluded that there was a problem with the question and it cost me 3000 chips to have the same solution I earlier explained to my daughter!

I am anxious to find out from daughter what has happened and she is still in school right now...


Posted by: Laila* on September 29, 2004 02:36 PM

There's something I don't understand Laila. how the problem mixes km with miles??? Or are the students supposed to convert miles into kilometres?


Posted by: Afonso on September 29, 2004 02:30 PM

Please write responsibly. Thank you!









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