math question

[tonykangus]

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anybody know how to solve this question?

A florist purchased three yellow roses, two pink roses and five red roses. How many three rose arrangements are possible?

 

[luder98]

anybody know how to solve this question?

A florist purchased three yellow roses, two pink roses and five red roses. How many three rose arrangements are possible?

I'm gonna charge you for all these questions. 😉 Do a search on Combination/Permutation on Google, and try out yourself. Got to go lunch now. I'll help you later.

 

[g3k]

anybody know how to solve this question?

A florist purchased three yellow roses, two pink roses and five red roses. How many three rose arrangements are possible?

I think it is 10!/ 7! ... I am not sure !!

 

[tonykangus]

I think it is 10!/ 3! ... I am not sure !!

you rew right.

5!/((5-3)!*3!)=10

I have another question.
Can you help me?

In a two dimensional coodinate system, point A=(3,-6) and point C=(7,6), and point B=(1,1). find the area of the triangle ABC

 

[RxTech]

you rew right.

5!/((5-3)!*3!)=10

I have another question.
Can you help me?

In a two dimensional coodinate system, point A=(3,-6) and point C=(7,6), and point B=(1,1). find the area of the triangle ABC

It's a combination question, therefore, order is not important

10!/3!(10!-3!) = 120

 

[g3k]

It's a combination question, therefore, order is not important

10!/3!(10!-3!) = 120

Really?? I thought it was permutation ...

 

[amino]

you rew right.

5!/((5-3)!*3!)=10

I have another question.
Can you help me?

In a two dimensional coodinate system, point A=(3,-6) and point C=(7,6), and point B=(1,1). find the area of the triangle ABC

This is a determinant problem....check out the following link:

http://www.purplemath.com/modules/detprobs.htm

and the following link will explain how to multiply it:
http://www.purplemath.com/modules/determs.htm

3 -6 1 3 -6
7 6 1 7 6
1 1 1 1 1

me thinks, but look at the link

 

[luder98]

Just want to correct one thing here, (10-3)! not 10!-3!.

 

[luder98]

This is a determinant problem....check out the following link:

http://www.purplemath.com/modules/detprobs.htm

Although this is a way to solve this problem, it involves way too much advanced math. I don't think there are that many DAT takers know what a 3x3 matrix is. Here is my way of solving this problem using basic algebra.

1. Find the distance between two of the three points.
2. Derive the equation through the two points
3. Find distance from the 3rd point to the line from (2)
4. 1/2 product of the two distances is the area

Another way to solve this is to use formula S = sqrt of p(p-a)(p-b)(p-c)

where:
a,b,c are the three segments
p = (a+b+c)/2

This problem is an overkill for DAT. I wouldn't worry about it.

 

[g3k]

Just want to correct one thing here, (10-3)! not 10!-3!.

HOW DO U DETERMINE IF IT IS COMBINATION OR PERMUTATION?

 

[RxTech]

you rew right.

5!/((5-3)!*3!)=10

I have another question.
Can you help me?

In a two dimensional coodinate system, point A=(3,-6) and point C=(7,6), and point B=(1,1). find the area of the triangle ABC

Area = f*g/2 -v*w/2

This is way too much work for a DAT problem...just skip it

 

[luder98]

HOW DO U DETERMINE IF IT IS COMBINATION OR PERMUTATION?

"Arrangement" sounds like order does not matter. (I'm an ESL student)Thus, in this case, it should be combination. For example, if you have two yellow and one red, if order doesn't matter (combination), you only have one case: 2 Ys and 1 R. But if order matters (permutation), you have three cases: YYR, YRY, RYY. Meaning that you have more cases in permutation. If you look at the two formulas, there is k! in the denominator of combination. That means you have less.

P = n!/(n-k)!
C = n!/[(n-k)!k!]

A special case of permutation is circular permuation. For the above example, YYR and RYY would be considered the same.

A few examples to give you a better idea: (n first, k second in my text)

1. How many ways can one pick 3 books out of his 10 books? Combination of 10, 3.

2. How many ways can one arrange 3 books from his 10 books on a shelf? Permutation of 10, 3.

3. How many ways can 6 people be lined up? Permutation of 6, 6.

4. How many ways can 6 people be seated around a circular table? Circular permutation of 6,6. In this case, it is (6-1)!/(6-6)! = 5!

Hope it helps.

 

[g3k]

"Arrangement" sounds like order does not matter. (I'm an ESL student)Thus, in this case, it should be combination. For example, if you have two yellow and one red, if order doesn't matter (combination), you only have one case: 2 Ys and 1 R. But if order matters (permutation), you have three cases: YYR, YRY, RYY. Meaning that you have more cases in permutation. If you look at the two formulas, there is k! in the denominator of combination. That means you have less.

P = n!/(n-k)!
C = n!/[(n-k)!k!]

A special case of permutation is circular permuation. For the above example, YYR and RYY would be considered the same.

A few examples to give you a better idea: (n first, k second in my text)

1. How many ways can one pick 3 books out of his 10 books? Combination of 10, 3.

2. How many ways can one arrange 3 books from his 10 books on a shelf? Permutation of 10, 3.

3. How many ways can 6 people be lined up? Permutation of 6, 6.

4. How many ways can 6 people be seated around a circular table? Circular permutation of 6,6. In this case, it is (6-1)!/(6-6)! = 5!

Hope it helps.

Thank you...
now taking the first q - A florist purchased three yellow roses, two pink roses and five red roses. How many three rose arrangements are possible?
and taking yr q no. 2 - How many ways can one arrange 3 books from his 10 books on a shelf? Permutation of 10, 3.
arranging 3 books from 10 books and 3 roses from 10 roses are the same arent they?? 😕
Thank u for taking the time in explaining it to me 😳

 

[luder98]

Thank you...
now taking the first q - A florist purchased three yellow roses, two pink roses and five red roses. How many three rose arrangements are possible?
and taking yr q no. 2 - How many ways can one arrange 3 books from his 10 books on a shelf? Permutation of 10, 3.
arranging 3 books from 10 books and 3 roses from 10 roses are the same arent they?? 😕
Thank u for taking the time in explaining it to me 😳

I know you're going to ask that question 🙂 In my question, I have "on the shelf", which means that order matters. YYR, YRY and RYY are all different. Hope that clears up the confusion.

 

[g3k]

I know you're going to ask that question 🙂 In my question, I have "on the shelf", which means that order matters. YYR, YRY and RYY are all different. Hope that clears up the confusion.

oh ok .... thank u so much