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| Author: | LM [ 24 Jan 2012, 10:01 ] |
| Post subject: | What is the value of length n<100 meter of wire? |
What is the value of length n<100 meter of wire? (1) When divided equal part of 10 meter each, a piece of 5 meter is left. (2) When divided equal of 6 meter each, a piece of 1 meter is left. |
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| Author: | Bunuel [ 24 Jan 2012, 10:12 ] |
| Post subject: | Re: DS-Length of wire |
LM wrote: What is the value of length n<100 meter of wire? 1) When divided equal part of 10 meter each, a piece of 5 meter is left. 2) When divided equal of 6 meter each, a piece of 1 meter is left. What is the value of length n<100 meter of wire? (1) When divided equal part of 10 meter each, a piece of 5 meter is left --> \(n=10q+5\): 5, 15, 25, ..., 95. Not sufficient. (2) When divided equal of 6 meter each, a piece of 1 meter is left --> \(n=6p+1\): 1, 7, 13, 19, 25, ..., 97. Not sufficient. (1)+(2) General formula of \(n\) based on \(n=10q+5\) and \(n=6p+1\) would be \(n=30m+25\) --> \(n\) can be: 25, 55 or 85. Not sufficient. Answer: E. To elaborate more. How to derive general formula of \(n\) based on \(n=10q+5\) and \(n=6p+1\): divisor will be the least common multiple of above two divisors 6 and 10, hence 30. Remainder will be the first common integer in above two patterns, hence 25. So, to satisfy both conditions, \(n\) must be of a type \(n=30m+25\): 25, 55 or 85. For more about this concept see: manhattan-remainder-problem-93752.html#p721341 when-positive-integer-n-is-divided-by-5-the-remainder-is-90442.html#p722552 when-the-positive-integer-a-is-divided-by-5-and-125591.html#p1028654 Hope it helps. |
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| Author: | Runner2 [ 25 Jan 2012, 10:27 ] |
| Post subject: | Re: What is the value of length n<100 meter of wire? |
clear explanation |
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| Author: | LM [ 25 Jan 2012, 20:39 ] |
| Post subject: | Re: DS-Length of wire |
Bunuel wrote: LM wrote: What is the value of length n<100 meter of wire? 1) When divided equal part of 10 meter each, a piece of 5 meter is left. 2) When divided equal of 6 meter each, a piece of 1 meter is left. What is the value of length n<100 meter of wire? (1) When divided equal part of 10 meter each, a piece of 5 meter is left --> \(n=10q+5\): 5, 15, 25, ..., 95. Not sufficient. (2) When divided equal of 6 meter each, a piece of 1 meter is left --> \(n=6p+1\): 1, 7, 13, 19, 25, ..., 97. Not sufficient. (1)+(2) General formula of \(n\) based on \(n=10q+5\) and \(n=6p+1\) would be \(n=30m+25\) --> \(n\) can be: 25, 55 or 85. Not sufficient. Answer: E. To elaborate more. How to derive general formula of \(n\) based on \(n=10q+5\) and \(n=6p+1\): divisor will be the least common multiple of above two divisors 6 and 10, hence 30. Remainder will be the first common integer in above two patterns, hence 25. So, to satisfy both conditions, \(n\) must be of a type \(n=30m+25\): 25, 55 or 85. For more about this concept see: manhattan-remainder-problem-93752.html#p721341 when-positive-integer-n-is-divided-by-5-the-remainder-is-90442.html#p722552 when-the-positive-integer-a-is-divided-by-5-and-125591.html#p1028654 Hope it helps. To elaborate more. How to derive general formula of \(n\) based on \(n=10q+5\) and \(n=6p+1\): divisor will be the least common multiple of above two divisors 6 and 10, hence 30. Remainder will be the first common integer in above two patterns, hence 25. So, to satisfy both conditions, \(n\) must be of a type \(n=30m+25\): 25, 55 or 85. Thanks very much. Above would have been very difficult to figure out in the real exam. |
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| Author: | TGC [ 11 Aug 2013, 09:36 ] |
| Post subject: | Re: What is the value of length n<100 meter of wire? |
N<100 What is N? (1). N =10A +5 ..... N can be 5,15,25,35 and so on INSUFFICIENT (2). N= 6B + 1 .... N can be 1,7,13,19,25 and so on INSUFFICIENT Combining (1).& (2). We get N = 30X + 25 N can be 25,55,85 Hence INSUFFICIENT (E) it is !! |
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| Author: | smyarga [ 30 Jul 2014, 03:14 ] |
| Post subject: | Re: What is the value of length n<100 meter of wire? |
Actually, this problem you can solve at most in 10 seconds:) The main point here is that all numbers with exact remainder form arithmetic progression with difference=divisor. For example, all x such that "when x is divided by 5 the remainder is 1" form arithmetic progression with first element 1 and difference 5: 1, 6, 11, 16, 21..... If 50<x<100 for example, I can definitely say that there are several such x, because the distance between all such numbers is 5. To solve this problem you need just to check if the divisor=(distance between numbers) large enough to have only 1 number inside interval. So, I need to find exact number less than 100. (1) The difference=divisor=10 is quite small for 100. Insufficient. (2) The difference=divisor=6 is quite small for 100. Insufficient. (1)+(2) The new difference=least common multiple of 10 and 6=30 is small for 100. Insufficient. The correct answer is E You don't really need here to write formula for x and first several values for each statement. |
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| Author: | shreyast [ 10 Mar 2015, 11:59 ] |
| Post subject: | Re: What is the value of length n<100 meter of wire? |
smyarga wrote: Actually, this problem you can solve at most in 10 seconds:) The main point here is that all numbers with exact remainder form arithmetic progression with difference=divisor. For example, all x such that "when x is divided by 5 the remainder is 1" form arithmetic progression with first element 1 and difference 5: 1, 6, 11, 16, 21..... If 50<x<100 for example, I can definitely say that there are several such x, because the distance between all such numbers is 5. To solve this problem you need just to check if the divisor=(distance between numbers) large enough to have only 1 number inside interval. So, I need to find exact number less than 100. (1) The difference=divisor=10 is quite small for 100. Insufficient. (2) The difference=divisor=6 is quite small for 100. Insufficient. (1)+(2) The new difference=least common multiple of 10 and 6=30 is small for 100. Insufficient. The correct answer is E You don't really need here to write formula for x and first several values for each statement. For (1)+(2), we need to know that the first number is 25. Only then we could say that this is insufficient. If the first number was >70, (1)+(2), could've been sufficient. |
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| Author: | sudhirgupta93 [ 21 Jul 2016, 03:57 ] |
| Post subject: | Re: What is the value of length n<100 meter of wire? |
LM wrote: What is the value of length n<100 meter of wire? (1) When divided equal part of 10 meter each, a piece of 5 meter is left. (2) When divided equal of 6 meter each, a piece of 1 meter is left. How about this? n < 100 ----- (1) S1- When divided equal part of 10 meter each, a piece of 5 meter is left. implies n = 10k + 5, where k is some integer 10k + 5 < 100 (from 1) solving k < 9.5 implies no unique solution for n as it can have multiple values. Therefore insufficient. S2- When divided equal part of 6 meter each, a piece of 1 meter is left. solving as above we get k < 16.5 which again means it is insufficient. Even combining S1 and S2 we don't reach a definite solution. Hence answer is E. |
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| Author: | gracie [ 24 Jan 2020, 11:17 ] |
| Post subject: | Re: What is the value of length n<100 meter of wire? |
LM wrote: What is the value of length n<100 meter of wire? (1) When divided equal part of 10 meter each, a piece of 5 meter is left. (2) When divided equal of 6 meter each, a piece of 1 meter is left. n=10q+5 n=6p+1 →10q-6p=-4 least values of q and p are 2 and 4 respectively substituting, least value of n=25 lcm of divisors 10 and 6=30 so 3 possible <100 meter values of n: 25, 55, 85 neither 1 nor 2 sufficient E |
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| Author: | bumpbot [ 15 Jan 2023, 07:17 ] |
| Post subject: | Re: What is the value of length n<100 meter of wire? |
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