UPSB v4
Off-topic / math hw help again
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Date: Sun, Aug 14 2011 04:34:34
so everyone in our class failed the long test, so our teacher was kind enough to give us a take home quiz and w/e score we get from this test = added to our score in the long test
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Date: Sun, Aug 14 2011 05:11:41
I mean sure bro some people can help you with this, but you gotta learn how to do them yourself. There is no point in having someone else do your work if you don't know how to do it yourself. It will hurt you in the long run. Just saying man.
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Date: Sun, Aug 14 2011 05:17:26
doing it too , just wanna make sure i get perfect cuz i got 13/35, even if i get 20 its just gonna give me 33, might even get 15 only here
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Date: Sun, Aug 14 2011 07:59:23
For your permutations worksheet. #1, given that an individual cannot have more than one position at any given time, the solution will be 9x8x7. #2, because all genre's must be kept together, there can only be three groups at any given time. Rock (r), pop (p), and classical (c) can be arranged as: r, c, p r, p, c c, p, r c, r, p p, c, r p, r, c #3, if the letters QUES must be reordered in a fashion that U and E cannot be next to each other, we are limited to a smaller set of combinations. Normally you will have these groups: QUES, QUSE, QSUE, QSEU, QESU, QEUS UQES, UQSE, USQE, USEQ, UEQS, UESQ EQUS, EQSU, EUQS, EUSQ, ESQU, ESUQ SQUE, SQEU, SUQE, SUEQ, SEQU, SEUQ If vowels cannot touch each other we can rule out the following: QUES, QUSE, QSUE, QSEU, QESU, QEUS UQES, UQSE, USQE, USEQ, UEQS, UESQ EQUS, EQSU, EUQS, EUSQ, ESQU, ESUQ SQUE, SQEU, SUQE, SUEQ, SEQU, SEUQ Sorry, I'm tired. If I made any mistakes, you now know why.
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Date: Sun, Aug 14 2011 08:44:45
sorry for bothering, my problem is test 1 # 3 and that quest shit only lol, thought it was hard...i really dont understand summation -.-
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Date: Sun, Aug 14 2011 08:58:55
'how many ways can your order the letters of QUEST so that vowels are never together' we have 5 'spaces' to put the 5 letters in. _ _ _ _ _ as 'QUEST' has 2 vowels and 3 consonants, the cases can be V C V C C, V C C V C, V C C C V, C V C V C, C V C C V, C C V C V (i think that is all), V = vowel, C = consonant (you can arrive at this conclusion by either listing cases out, or calculating it using 'C' thingy on calculator etc) for a general case, find the number of ways the 3 consonants can be arranged, and the number of ways the 2 vowels can be arranged, and multiply the 2 numbers (think logically about this for a few seconds to see why xD) QUEST has Q, S, T as consonants, and U and E as vowels so number of ways the 3 consonants can be arranged is 3 factorial = 3! = 6 (Q S T , Q T S , S Q T , S T Q , T Q S , T S Q); number of ways the 2 vowels can be arranged is 2! = 2 (U E and E U) so number of ways for arrangement is 6 x 2 = 12 for each case --> total number of ways for arrangements for all 6 cases = 12 x 6 = 72 edit: i think i have counted all possibilities...i think xD
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Date: Sun, Aug 14 2011 09:05:17
lol even my classmates dont get how to do the quest thing...whoever created permutations/ combinations is a fag...fucking OC -.- who cares about arrangements...no ones gonna make a million arrangements lol
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Date: Sun, Aug 14 2011 14:15:02
Aha, perms and combs. This is where cubing knowledge come in useful. 1) Out of 9 people, 3 are chosen for 3 posts. Therefore, 9C3. If you have that Casio calculator, press [9], [shift][divide] and 3. I don't use formulas :) 2) 4 rock, 5 pop and 6 classical. Total of 15 albums. Each genre kept together. Now this is a rather fun case. My teacher has an interesting way of putting it. She says if the question mentions grouping something together, we imagine it tied up. So, we tie up the rock genre first. Treat all the rock genre albums as one. Now we have 12 albums in total. So, you know if positons matter in the question it has gotta be a permutation case. So the first part of the equation would be 12! x 4! Remember the 4 rock albums can be freely arranged, thus 4!. And now the same for pop and classical genres. If you do the same you should have a complete equation like this: (12! x 4!) x (11! x 5!) x (10! x 6!) Use the calculator, it'll make life much easier. 3) Number of ways to arrange 'QUEST' without vowels next to each other. Okay, there are 2 vowels. The possible arrangements are (v denoted for vowel): v_v_ _ _v_v_ _ _v_v_ So, that's 3 possible types of arrangement. Let's go a little more in depth. The word 'QUEST' has 5 letters, and there are 3 spots for consonants 'q', 's' and 't'. Look at the first type of arrangment first: v_v_ _ The first spot could be either 'q', 's' or 't'. Leaving the other 2 free to be the other two left. So for the first type, the equation would be 3P1 x 2! x 2! 3P1 because there are 3 possibilities for the first spot, 2! for the other 2 consonants and remember the two vowels can switch places. And then you simply multiply the above equation by 3 because there are 3 possible types of arrangements. I'm not 100% sure, but it should most definitely be correct :O 4) Simple. It's clearly a combination case, since order does not matter. 35C17. 5) Even simpler. Since there are no restrictions, and 'MATHEMATICS' contain 11 letters, 11!. 6) If I understand the question correctly it should mean how can I arrange 24-28 (ex. 25, 24, 27...). Since there are 5 items to be arranged, 5!. (Again, not really sure what the question wants) 7) a) Similar to no. 2, we type up the two people. That leaves us with 4 people. So, 4P2 x 2! because the two are free to switch places. b) Please refer to no. 3 and apply, as I'm getting tired of typing :P 8) REFER TO QUESTION 7. Why are the questions so similar? Hope it helps @Clyde :)
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Date: Sun, Aug 14 2011 14:21:43
thx for the help, quest and the summation was really my problem, you sure with the albums it has to be that way? imma check my classmates hw's tomorrow to make sure...cuz im sure its just 4!5!6!
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Date: Sun, Aug 14 2011 14:26:02
i think krypton didn't account for repetitions in some of the later q's (like 'mathematics' has 2 A's and 2 T's and 2 M's, so answer is 11! / (2! * 2! * 2!), so 11!/8 for that question :P edit: since i'm bored and i have no life at 12:30 at night, i will check albums q. arrange albums in groups of 4,5,6 with same genres together. so, we can order the groups in 3! different ways (RCP, RPC, CRP, CPR, PCR, PRC) = 6 ways for each group, we need to find number of ways in which we can arrange albums, because: number of ways for RCP, for example, = (number of ways to arrange rock albums) * (number of ways to arrange classical albums) * (number of ways to arrange pop albums) = 4! * 6! * 5! for RCP order this is the same for the other orders (RPC, CRP etc all have 4! * 5! * 6! ways each) so total for the question is 6 * 4! * 5! * 6! = some large number @Clyde
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Date: Sun, Aug 14 2011 14:27:04
SHIT. You're right. I misread the question and typed all that bullshit ;____; But there's something. You gotta multiply a 3! because the rock, pop and classical can switch places. So it's just 3! x 4! x 5! x 6!. Yeap, @i.suk's right. Tie up the repeated letters and treat it as one. Thanks for catching it :)
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Date: Sun, Aug 14 2011 16:41:53
CHEATER.
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Date: Mon, Aug 15 2011 08:19:28
nobody got the quest right lol everyone copied wrong shit from each other, probably gonna get 15~17 here