Friday, March 7, 2008

Scribe Post

Hello everyone, on with the post now.

Today in the morning class we quickly went over the homework of two days ago, and then were separated into groups for a workshop (since we are done with the unit). The answers for the homework can be seen on the slides posted by Mr. K.

When we started the workshop we had a simple question, relating to Pascal's triangle.

Keep in mind that the numbers in orange are the total amount of ways of getting from A t C as well as from A to B, passing through point P. The numbers in green are the total amount of ways from C to D and finally the numbers in blue are from D t B. If you multiply all of the results (excluding point P) you will get the total amount of ways to get from A to B, which is 6x2x10 = 120

We handed that in for marks, then were left with harder problems to solve within our group. Whichever group had someone go up on the board with a solution would get points (marks).

We did many of those on the afternoon class as well, so I'll just summarize the ideas here.

"Design an experiment using the random number
function of your calculator to determine the
probability of passing a six-question multiple choice
test if you guess all the answers. Each question has
four answers, and one answer is correct in each case.
How many simulations would seem reasonable? What
is the experimental probability of getting at least 50%
on the test?"

For this problem we had 3 different solutions, that were all close to the real value. You you'd need your randBin function of your calculator for it, with the numbers (6, 1/4, 5) meaning that every result you'll have 5 numbers showing, ranging from 0 through 4, for the 6 questions in the problem.

The question after that we had to remember the difference between Pick formula and the Choose formula, being that the order of the numbers matters for Pick formula (I use the saying P is for picky to remember that)

"A party of eight boys and eight girls are going for a picnic. Six of the party can
ride in one car, and four in another. The rest must walk. (Assume anyone can

For this problem we used the choose formula to solve, since the orders of boys and girls do not matter. Remember that even though we did it in separate steps in class, we will most likely be asked the last question in a test.

Finally we were asked a simple question again:
"Fred is in a class that has 7 boys and 15 girls. The teacher selects partners for
a project by drawing names from a hat. What is the probability that Fred's
partner will be a boy?"

The solution for that was rather easy so I'll just explain what to do. Since Fred himself is one of the 7 boys in his class, there are only 6 other boys that can be his partner, and there are 15 girls, making it a total of 21 possible partners. So, his chance of being teamed up with a boy is 6/21, or 29%.

Well, that's all we did today. Remember to do your BOB posts since our test is on Tuesday. Bring up any questions for Monday's class, which we will use for a pretest.

And... the next scribe is..... *drum roll*
JESSIE. Good luck, haha.

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