Matrix Exercise 5- 2,3.

Sept. 12th 2008.

Hey everyone, today we corrected Exersise 5 questions 2, and 3. I'm having a little trouble with this so bare with me as i try to explain it.

Question number two gives us a diagram of the two types of factories that produce kitchen and bedroom suits. The corporation has 3 factories of type A and 8 factories of type B. Kitchen suites sell for $1500.00 and bedroom suites sell for $2200.00. Now that we got all the information we can now use a matrix operation to determine the questions they gives us.

We have to find the weekly production of kitchen and bedroom suits.

If you look at the top of the notes you notice K and B in the rows, that stands for Kitchen and Bedroom. The A and B in the column stand for Factory A and Factory B.

We have a 2x2 matrix and a 2x1 matrix. The twos on the inside match so that means we are able to multiply these matricies. The numbers on the outside which are 2 and 1 mean we will have two rows and one column in this answer. So you do the multiplication and end up with the answer K=170
B=240 (with brackets)

Now, we are asked to find the total market value of the goods purchased.

So, we know for the Kitchen suites they sell for $1500.00 and the Bedroom suites sell for $2200.00. Which makes a 1x2 matrix.

You experiment now with these too see if you will mulitply them in the order of (2x1)(1x2) or a (1x2)(2x1).
It seems possible with the (2x1)(1x2) because the ones match in the inside so that means you are able to multiple them and come up with a two by two answer. But in this case, it is nonsense!! Two of your answer in your 2x2 matrix are numbers that don't make sense, don't exist, won't help you. What you need to do is flip the question around so you are multipling (1x2)(2x1) so you get a 1x1 answer. The total cost of kitchens and bedrooms is $783 000.


Now questions number three does not give us a matrix diagram so we have to do that on our own. When you are reading the question to make writing a matrix easier writing
down little notes like what Mr. Maks did helps in the end.

So, nine two story houses and six bungalows.(For those who don't know what a bungalow is, it is a one story house.) One two story house needs 1600 units of materials and 2000 hours of labour. One bungalow requires 1500 units of material and 1800 hours of labour. Labour costs $12.00 per hour and materials cost $20.00.

We first need to find the totaly units of materials and hours of labour needed to complete this job site.

With the proper matricies in the proper order as shown above we are able to get a 1x2 answer of the units of materials and hours of labour.

Second questions asks us to dermine the cost of building a two storey house and a bungalow.

What Mr. Maks was showing use was that multipling the 20 to the 1600 makes sense because they are both units of materials but multipling the 12 and 1500 is nonsense because one of them is units of materials and the other number is hours of labour. Doesn't match and doesn't make sense. You have to flip it around to make it a 2x1 matrix so you are able to multiply it correctly and get a 2x1 answer. The cost of a two story house and a bungalow. Add those two numbers and you get the answer to your last question. What is the total cost of developing the site?

I hope this helps anyone who missed this class or didn't understand it. If you have any questions please ask me and will will gladly help!