[URGENT HELP] maths problem

erarkku · #1 $Old$ July 6th, 2009, 05:18 AM

heyy people of maths help forum i'm facing troubles of my own solving this question

a manufacture makes hi-fi systems and sells it to the wholesaler for 15% + cost of making , the wholesaler then sells it to the retailer at price + 20%, then the retailer sells to ME at $1470 including 30% of it is profit for the retailer.

find the cost of making the hi-fi system whopss forgot to add that sorry.

Swlabr · #2 $Old$ July 6th, 2009, 06:07 AM

Quote:

Originally Posted by erarkku $View Post$

heyy people of maths help forum i'm facing troubles of my own solving this question

a manufacture makes hi-fi systems and sells it to the wholesaler for 15% + cost of making , the wholesaler then sells it to the retailer at price + 20%, then the retailer sells to ME at $1470 including 30% of it is profit for the retailer.

find the cost of making the hi-fi system whopss forgot to add that sorry.

The "trick" to these questions is make them into equations.

Let $x$ be the cost of making the system. So,

the wholesaler bought it for $y=x + (15$ % $\text{of } x) = x + 0.15x=1.15x$ ,

the retailer bought it for $z=1.20y$ ,

and you bought it for $1470=1.30z$ .

Now, substitute everything into the last equation. $1470=1.30z=1.30*(1.20y)= \ldots$ , and then you will have an equation that is only in terms of $x$ , which is what you wish to find. So, just solve for $x$ .

Sooda · #3 $Old$ July 6th, 2009, 02:40 PM

Solving this problem like Swlabr suggested seems professional way. Though I prefer step by step explanations and answers, that way I can examine and learn more.
Math should be logical (that is why I registered here -- to learn). I have finished high school in USA terms and have idea how to get answer.

I am going to subtract percentages until I get manufacturer production cost, it should be possible.

30% from 1470 is 1470 * 0.3 = 441, Retailer got it for 1470 - 441 = 1029
20% from 1029 is 1029 * 0.2 = 205.8,Wholesaler got it for 1029 - 205.8 = 823.2
15% from 823.2 is 823.2 * 0.15 = 123.48, Manufacturer production cost was 823.2 - 123.48 = 699.72 ($)

Hi-fi system costs 699.72 $.

I am learning by doing.

Swlabr · #4 $Old$ July 8th, 2009, 03:08 AM

Quote:

Originally Posted by Sooda $View Post$

Solving this problem like Swlabr suggested seems professional way. Though I prefer step by step explanations and answers, that way I can examine and learn more.
Math should be logical (that is why I registered here -- to learn). I have finished high school in USA terms and have idea how to get answer.

I am going to subtract percentages until I get manufacturer production cost, it should be possible.

30% from 1470 is 1470 * 0.3 = 441, Retailer got it for 1470 - 441 = 1029
20% from 1029 is 1029 * 0.2 = 205.8,Wholesaler got it for 1029 - 205.8 = 823.2
15% from 823.2 is 823.2 * 0.15 = 123.48, Manufacturer production cost was 823.2 - 123.48 = 699.72 ($)

Hi-fi system costs 699.72 $.

I am learning by doing.

Hi, I appologise for my delay in replying.

However, I would like to point out that your answer is actually incorrect. You said:

Quote:

Originally Posted by Sooda $View Post$

30% from 1470 is 1470 * 0.3 = 441, Retailer got it for 1470 - 441 = 1029

and so on. What you are doing here is finding 30% of the final cost, not of the initial cost. These are different. To put it in equations:

$1470 * 0.3 = 441 \neq 1029*0.3$ , where $1029*0.3$ would be the profit from that stage if they had bought it for 1029.

I hope that makes sense.

Basically, your problem is that you are finding the percentages of the final price not of the price that the seller, maker, etc bought it for, and these percentages are different.

The final answer is, I believe, £819.40 by rounding.

Swlabr · #5 $Old$ July 8th, 2009, 04:36 AM

Quote:

Originally Posted by Stroodle $View Post$

You need to make your spam a bit shorter. No-one's gonna read that chunk of text...

I don't think your meant to read it, just click the links. His other posts are the same (see the Geometry forum), just with different issues being discussed.

Also, I like your avatar...!

Sooda · #6 $Old$ July 8th, 2009, 05:24 AM

Interesting to know, maybe one day I can solve problems correctly.

Swlabr · #7 $Old$ July 8th, 2009, 06:03 AM

Quote:

Originally Posted by Sooda $View Post$

Interesting to know, maybe one day I can solve problems correctly.

It just takes practice, that's all.