another one

lovethegto · 2010-10-30 04:39:12

could i get some help again? thank you

joe invested $5400 in two accounts, a CD account paying 8% and a money market account paying 10% if both investments produce the same amount of interest, how much was invested at 8%

bobbym · 2010-10-30 05:05:57

Hi lovethegto;

I am assuming you mean he split the 5400 up into the 2 different investments.

For these type of problems you must milk all the information you can get out of the question.

If we say C is the money invested in the CD account and M the money invested in money marketing, then we have the following relationships.
Also we call the interest earned I.

This is a 3x3 linear simultaneous set and is easy to solve,

C = CD account = $3000

M = money market = $2400

I = interest earned = $480

That is the long rote way that requires little thinking but will always get the job done. I use it when I do not see a quicker way.
Here is a much faster way.

10% is 5 / 4 of 8% so just solve:

x = 2400 so 5 / 4 of x = 3000.

.08 * 3000 = 240 and .1 of 2400 = 240 so:

CD = $3000, money market = $2400, Interest = 240 + 240 = $480

lovethegto · 2010-10-30 17:27:15

thank you again... your saving my butt;)

bobbym · 2010-10-30 17:41:58

Glad to help!

lovethegto · 2010-10-30 17:43:27

i dont know how to put this one into a table

bobbym · 2010-10-30 17:48:20

Hi;

I do not either. Do you have an example one that you can show to me?

lovethegto · 2010-10-30 18:19:41

amount $ invest | Interest | duration of loan|
-------------------|-----------|-------------------|
X | .08 | 1 yr |
-------------------|-----------|-------------------|
5400-X | .10 | 1 yr |
----------------------------------------------------
something like that?

bobbym · 2010-10-30 19:18:47

Hi;

Is this what you want? According to the web pages I am now looking at this is what they are teaching. It should suffice.

Begin Rant:

I just want to say that a rather nasty professor said I reasoned like a dog ( Yes that is what she said, a DOG!) when I solved a problem using that method.

At another forum the professor types over there said my work was incomprehensible gibberish when I just suggested solving a problem in that manner and now they are teaching it to kids!!!!!!!
Ahhhhhhhhhhhhh!!!! That is me screaming! Unfair! Woof! Woof!

Might I just say that the above method is for a computer! Not for a human being! They should not be teaching it as a viable method.
The solution is so contrived as to be absurd. I refuse to be an Atari with hair. In protest to their teaching method, I made the above table using a computer, Ha! This DOG bites!

End Rant:

Okay,lovethegto, go here to see more of these type of problems.

http://library.thinkquest.org/25459/lea … table.html

lovethegto · 2010-10-31 06:37:37

Thank you for all your help! yeah she it hard at times

bobbym · 2010-10-31 07:15:58

Hi lovethegto;

If you do not pick the right stepsize, in this case 600 you might completely skip over the answer.
That is another reason I am not happy with her algorithm.

Math Is Fun Forum

#1 2010-10-30 04:39:12

another one

#2 2010-10-30 05:05:57

Re: another one

#3 2010-10-30 17:27:15

Re: another one

#4 2010-10-30 17:41:58

Re: another one

#5 2010-10-30 17:43:27

Re: another one

#6 2010-10-30 17:48:20

Re: another one

#7 2010-10-30 18:19:41

Re: another one

#8 2010-10-30 19:18:47

Re: another one

#9 2010-10-31 06:37:37

Re: another one

#10 2010-10-31 07:15:58

Re: another one

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