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Take home test math problem

Posted: Wed Apr 11, 2007 1:03 pm
by Naethyn
My intermediate algebra teacher gave us a take home test. The bonus question at the end of the test is really gay. He has said that no one in the 10 years he has worked there has turned in the correct answer. Now I come to none other than the NT to vanquish it! Ok here goes:

"Bob can run 35 miles in one hour less time than it takes bill to run 48 miles. Bob can run 50 miles in three hours more time than it takes bill to run 42 miles. Find bob's speed and bill's speed."

He requested I show my work.

Lets see if the NT can do it! haha (cause i certainly can't)

Posted: Wed Apr 11, 2007 1:16 pm
by Spazz
You know I cant .

Posted: Wed Apr 11, 2007 1:20 pm
by Gaazy
7
whenever in doubt, just write 7

Posted: Wed Apr 11, 2007 1:24 pm
by Snero
bob = 5 mph
bill = 6 mph

Posted: Wed Apr 11, 2007 1:34 pm
by Evermore
Snero wrote:bob = 5 mph
bill = 6 mph



you didnt show your work

Posted: Wed Apr 11, 2007 1:40 pm
by Arlos
Actually, unless I got my math wrong, Bob = 1/5mph and Bill= 1/6 mph.

Your school must not have a lot of good math people, as the problem is just a simple substitution. He verbally gives you 2 equations with 2 variables. Just solve 1 equation for 1 of the variables, and substitute it into the other equation.

Let x = Bob's speed in mph and let y = Bill's speed in mph.

Figure out the 2 equations from the sentance he gave you, solve the first one for x, and then plug that into the 2nd equation, and that'll give you a numeric value for y.

-Arlos

Posted: Wed Apr 11, 2007 1:47 pm
by Snero
bah fine, it's a simple substitution

the first equation, if t is the time
x = bob's speed
y = bill's speed

35m = x (t-1) this means bob does 35 miles in a given time - 1 hour at his speed
48 = yt Bill does 48 miles over the given period x his speed

if you isolate t in the second equation you get 48/y = t, and then substitute t in the first equation, you can completely eliminate t

35 = x(48/y-1) This is the first major equation

then the second part

50= x(t+3)
42 = yt

t=42/y

so substituting t into the previous equation

50=x(42/y+3) and here is the other major equation

here you have 2 equations with 2 variables, easily solvable

35 = x(48/y-1)
50=x(42/y+3)

isolate x in each 35/(48/y-1) = x = 50/(42/y+3)

35(42/y+3) = 50 (48/y-1)
1470/y + 105 = 2400/y -50 ____multiply by y
1470 + 105y = 2400 -50y
155y = 930
y=6

substitute y=6 into 50=x(42/y+3)

50 = x(42/6 +3)
50 = x(7 + 3)
50= 10x
x=5

Posted: Wed Apr 11, 2007 1:54 pm
by Arlos
Yah, you're right, I messed up my initial substitution equations. I will now go sit in the box and feel shame.

-Arlos

Posted: Wed Apr 11, 2007 1:54 pm
by Snero
arlos, Distance = Speed x Time

Posted: Wed Apr 11, 2007 2:02 pm
by Naethyn
Wow Snero thanks! im taking this in tomorrow,

and yes, its a community college. (the people are retarted as well as the teachers)

Thankfully I'll be at the university this fall. (im considered in state now woot!)

Posted: Wed Apr 11, 2007 2:07 pm
by Jay
Hey man, over 50% of all college students go through CC before they hit university level and I can tell ya that my CC's professors were 9340239409x better than my university professors.

Posted: Thu Apr 12, 2007 6:47 am
by Eziekial
Cheater. Let me know what he says. I bet it was just a ploy to get everyone to do the equation.

Posted: Thu Apr 12, 2007 11:11 am
by Phlegm
Naethyn wrote:Wow Snero thanks! im taking this in tomorrow,

and yes, its a community college. (the people are retarted as well as the teachers)

Thankfully I'll be at the university this fall. (im considered in state now woot!)


I hope you're not going major in math or science.

Posted: Thu Apr 12, 2007 11:24 am
by Naethyn
Computer Information Systems - Programming

Cool I turned it in and he made me explain how it worked on the board for the class. Got 5 extra points. Gogo NT!

Posted: Thu Apr 12, 2007 2:25 pm
by Harrison
Cheating is cool, we need more under-qualified people with degrees.

Posted: Thu Apr 12, 2007 2:26 pm
by Tacks
At least he went to school.

Posted: Thu Apr 12, 2007 2:27 pm
by Harrison
:dunno:

Posted: Thu Apr 12, 2007 3:05 pm
by Naethyn
I didn't cheat at all. It's a takehome test. As in take the test home and use any fucking resources possible to get the correct answer. Atleast thats my definition.

I got my A and thats all that matters to me. In fact it was a 105 because of the work snero did =p

Posted: Thu Apr 12, 2007 7:20 pm
by Evermore
Naethyn wrote:I didn't cheat at all. It's a takehome test. As in take the test home and use any fucking resources possible to get the correct answer. Atleast thats my definition.

I got my A and thats all that matters to me. In fact it was a 105 because of the work snero did =p


you owe snerp some oral

Posted: Thu Apr 12, 2007 7:21 pm
by Evermore
Harrison wrote:Cheating is cool, we need more under-qualified people with degrees.


need more dishwashers and trashmen too

Posted: Thu Apr 12, 2007 7:47 pm
by 10sun
Evermore wrote:
Harrison wrote:Cheating is cool, we need more under-qualified people with degrees.


need more dishwashers and trashmen too


Ahem, sanitation engineers.

Posted: Thu Apr 12, 2007 8:22 pm
by Menlaan
More power to you. If you successfully went to the board to explain it to the class, then you must learned something from the exercise. You also showed resourcefulness. Sure, it would have been better if you knew the answer before asking, but good for you for learning regardless of your means.

Congrats too on the 105!

Posted: Thu Apr 12, 2007 10:07 pm
by Markarado
Good for you bro. The idea is to learn. Who cares how you do it.

Posted: Thu Apr 12, 2007 11:00 pm
by Xaiveir
Markarado wrote:Good for you bro. The idea is to learn. Who cares how you do it.



I care god damn it!

Posted: Thu Apr 12, 2007 11:00 pm
by Xaiveir
Ok not really, Good job man. Nice work.