akshayxyz Posted December 18, 2011 Author Posted December 18, 2011 Student is right..There is no way a southie heading towards north' date=' it must be other way around.[/quote'] :two_thumbs_up: This is so applicable in various contexts.
akshayxyz Posted December 18, 2011 Author Posted December 18, 2011 The question does not say that Marie is perfectly ambidextrous and does not say if she has equal power in both hands.. In absence of any specific information, we will have to assume that she is not ambidextrous like most of the world's population. Also, for the two hands theory to work, she has to have two saws of equal size, shape, strength and sharpness. It will work only if: 1. Marie is perfectly ambidextrous - meaning exactly equally skillful in both hands. 2. Marie has perfectly equal strength in both hands. 3. Marie has two saws. 4. Both saws are of equal size 5. Both saws are of equal strength. 6. Both saws have equal sharpness. Definitely not required in this particular question, as it is supposed to be test of a mathematical concept, and context is usually even more well defined by the syllabus. As for OP, it is just a play on teacher's mistake..But, in general that is how open ended questions are like forcing the candidate to ask questions, make assumptions..think beyond mugged up knowledge and what is on the table and then correlate the facts and assumptions towards any conclusion. Final answer is immaterial in such discussions, ability to analyze and logically connect the dots is more important. Every single condition listed above is highly unlikely. Hence It's almost impossible for them all to be true. Accounting for all sorts of probabilities and stuff will make it a research paper :)
zen Posted December 18, 2011 Posted December 18, 2011 How is this a serious issue? If the paper with the diagram is being moved all over the place' date=' why would the directions remain constant? [b']The student is wrong, when the directions are mentioned in the question paper, it is given (i.e, has to be assumed) that its to be taken as the compass direction. I know it was not a serious question A nice eg of duhism Nah, this is a serious question attempting to seek alt solutions and look past common sense to create problems where none exists (this is what the thread is abt, IMO, I.e. ignore common sense in the name of alt sol) :P
zen Posted December 18, 2011 Posted December 18, 2011 The question does not say that Marie is perfectly ambidextrous and does not say if she has equal power in both hands.. In absence of any specific information, we will have to assume that she is not ambidextrous like most of the world's population. Also, for the two hands theory to work, she has to have two saws of equal size, shape, strength and sharpness. It will work only if: 1. Marie is perfectly ambidextrous - meaning exactly equally skillful in both hands. 2. Marie has perfectly equal strength in both hands. 3. Marie has two saws. 4. Both saws are of equal size 5. Both saws are of equal strength. 6. Both saws have equal sharpness. Every single condition listed above is highly unlikely. Hence It's almost impossible for them all to be true. I love reading posts like the above^ .... at times, even remind me of ganesharan's posts :haha: Imagine a person is brought in the court to provide evidence: A: Please place your hands on Gita and swear that you will speak only the truth *B shocked by the statement, rises and speaks out. He cannot believe how the court could be so naive* B: Excuse me? How can you be so sure that the man will not lie under the oath? There is no evidence to suggest that ppl always speak the truth under the oath. Ppl are known to even beat lie detectors. Until we develop a scientifically proven system which can measure that ppl don't lie under the oath, we can't be 100% sure that ppl don't lie under the oath. *B sits down feeling he made a great point and thinking how smart he is to see what no one else could, while everyone else is :facepalm: *
CasualVisitor Posted December 18, 2011 Posted December 18, 2011 How about this. [ i = sqrt(-1) ] See whether you can figure out the fallacy here :) Cannot pinpoint the issue but the result we reach at step 4 seems wrong. Step 4 gives us 1/i = i/1 which means i ^ 2 = 1. We started with i ^ 2 = -1. So, something before step4 is inaccurate. It cannot be step1, so it has to be either step2 or step3.
akshayxyz Posted December 18, 2011 Author Posted December 18, 2011 Cannot pinpoint the issue but the result we reach at step 4 seems wrong. Step 4 gives us 1/i = i/1 which means i ^ 2 = 1. We started with i ^ 2 = -1. So' date=' something before step4 is inaccurate. It cannot be step1, so it has to be either step2 or step3.[/quote'] As I already posted - both step 2 and 3 are wrong., but the fallacy arises from the error in Step 3..
Vijay.Sharma Posted December 18, 2011 Posted December 18, 2011 I love reading posts like the above^ .... at times, even remind me of ganesharan's posts :haha: Imagine a person is brought in the court to provide evidence: A: Please place your hands on Gita and swear that you will speak only the truth *B shocked by the statement, rises and speaks out. He cannot believe how the court could be so naive* B: Excuse me? How can you be so sure that the man will not lie under the oath? There is no evidence to suggest that ppl always speak the truth under the oath. Ppl are known to even beat lie detectors. Until we develop a scientifically proven system which can measure that ppl don't lie under the oath, we can't be 100% sure that ppl don't lie under the oath. *B sits down feeling he made a great point and thinking how smart he is to see what no one else could, while everyone else is :facepalm: *That was a little harsh on him
CasualVisitor Posted December 18, 2011 Posted December 18, 2011 Cannot pinpoint the issue but the result we reach at step 4 seems wrong. Step 4 gives us 1/i = i/1 which means i ^ 2 = 1. We started with i ^ 2 = -1. So' date=' something before step4 is inaccurate. It cannot be step1, so it has to be either step2 or step3.[/quote'] Think I found it . In step 4, square root of 1 is replaced with 1. But you cant be sure about that as square root of 1 could be either +1 or -1. If one replaces LHS with 1 and RHS with -1 then one cannot reach to 1=2. So IMO, replacing square root of 1 with 1 is the root cause. Can my near-two-decade old math knowhow be relied upon :winky: ?
zen Posted December 18, 2011 Posted December 18, 2011 Another question: Jack and Jill went up the hill to fetch a pale of water. * the well is 1000mts away * jack can run at 100 kmph * jill can run at 80 kmph calculate how long would it take for them to fetch the water, if both of them held the pale together? possible drawbacks to the question above: * that speed is similar to cheetah's, humans are not known to run this fast * we don't know if the speeds given are measured on a flat ground, running downhill or uphill :P
Vijay.Sharma Posted December 18, 2011 Posted December 18, 2011 Think I found it . In step 4' date=' square root of 1 is replaced with 1. But you cant be sure about that as square root of 1 could be either +1 or -1. If one replaces LHS with 1 and RHS with -1 then one cannot reach to 1=2. So IMO, replacing square root of 1 with 1 is the root cause. Can my near-two-decade old math knowhow be relied upon :winky: ?[/quote']Oh yes it can be....nice catch :icflove:
akshayxyz Posted December 18, 2011 Author Posted December 18, 2011 Think I found it . In step 4' date= square root of 1 is replaced with 1. But you cant be sure about that as square root of 1 could be either +1 or -1. If one replaces LHS with 1 and RHS with -1 then one cannot reach to 1=2. So IMO, replacing square root of 1 with 1 is the root cause. Can my near-two-decade old math knowhow be relied upon :winky: ? no that is not the problem, as long as you are taking same sign on both sides., as pointed out earlier - culprit is step 3 ( step 2 is wrong too, but not root of the fallacy).
zen Posted December 18, 2011 Posted December 18, 2011 That was a little harsh on him ooops may be .... but was mainly referring to the post and many of us make such posts at times
Vijay.Sharma Posted December 18, 2011 Posted December 18, 2011 Another question: Jack and Jill went up the hill to fetch a pale of water. * the well is 1000mts away * jack can run at 100 kmph * jill can run at 80 kmph calculate how long would it take for them to fetch the water, if both of them held the pale together? possible drawbacks to the question above: * that speed is similar to cheetah, humans are not known to run this fast * we don't know if the speeds given are measured on a flat ground, running downhill or uphill :PAlright now you are going overboard
zen Posted December 18, 2011 Posted December 18, 2011 Alright now you are going overboard that's a serious question :orderorder: answer assuming the data in the question can be applied to the situation
nikred Posted December 18, 2011 Posted December 18, 2011 Another question: Jack and Jill went up the hill to fetch a pale of water. * the well is 1000mts away * jack can run at 100 kmph * jill can run at 80 kmph calculate how long would it take for them to fetch the water, if both of them held the pale together? possible drawbacks to the question above: * that speed is similar to cheetah's, humans are not known to run this fast * we don't know if the speeds given are measured on a flat ground, running downhill or uphill :P How do you know Jack and Jill are humans. It could be they are cheetahs after all. But then how can cheetahs fetch water from the well. Maybe they are aliens who are capable of tremendous speeds and as skillful as humans in handling tools.
zen Posted December 18, 2011 Posted December 18, 2011 How do you know Jack and Jill are humans. It could be they are cheetahs after all. But then how can cheetahs fetch water from the well. Maybe they are aliens who are capable of tremendous speeds and as skillful as humans in handling tools. :haha: any alt solution?
CasualVisitor Posted December 18, 2011 Posted December 18, 2011 How do you know Jack and Jill are humans. It could be they are cheetahs after all. But then how can cheetahs fetch water from the well. Maybe they are aliens who are capable of tremendous speeds and as skillful as humans in handling tools. :hysterical::hysterical::hysterical:
zen Posted December 18, 2011 Posted December 18, 2011 rett, who is said to have poor math skills attempts his own grade 2 question: Jack (whether a human or cheetah) runs @ 100 kmph Jill (see above) runs @ 80 kmph distance to the well = 1 km total distance = 2 kms should take the avg of Jack and Jill's speed? :hmmmm: .............. ............ Nah, Jack will have to run slowly as Jill can't run faster than 80kmph, so the time taken by both of fetch a pale of water would be the same time Jill would take :two_thumbs_up:
Vijay.Sharma Posted December 18, 2011 Posted December 18, 2011 rett, who is said to have poor math skills attempts his own grade 2 question: Jack (whether a human or cheetah) runs @ 100 kmph Jill (see above) runs @ 80 kmph distance to the well = 1 km total distance = 2 kms should take the avg of Jack and Jill's speed? :hmmmm: .............. ............ Nah, Jack will have to run slowly as Jill can't run faster than 80kmph, so the time taken by both of fetch a pale of water would be the same time Jill would take :two_thumbs_up:You forgot to account for this item - Jack and Jill's speeds are assuming they are running without having to carry anything. So when they are carrying water their speeds will be lesser....lol
DomainK Posted December 18, 2011 Posted December 18, 2011 I love reading posts like the above^ .... at times, even remind me of ganesharan's posts :haha: Imagine a person is brought in the court to provide evidence: A: Please place your hands on Gita and swear that you will speak only the truth *B shocked by the statement, rises and speaks out. He cannot believe how the court could be so naive* B: Excuse me? How can you be so sure that the man will not lie under the oath? There is no evidence to suggest that ppl always speak the truth under the oath. Ppl are known to even beat lie detectors. Until we develop a scientifically proven system which can measure that ppl don't lie under the oath, we can't be 100% sure that ppl don't lie under the oath. *B sits down feeling he made a great point and thinking how smart he is to see what no one else could, while everyone else is :facepalm: * Check the battery on your sarcasm detector. :headshake:
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