One number, n, is selected at random from a set of 10 integers. What is the probability that ½ n + 13 = 0 ?
1. The largest integer in the set is 13.
2. The arithmetic mean of the set is zero.
Probability + DS
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- harsh.champ
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(1) We know that the largest integer of the set is 13 but we know nothing about the lowest number, which could be up to - infinity. INSUFF.harsh.champ wrote:One number, n, is selected at random from a set of 10 integers. What is the probability that ½ n + 13 = 0 ?
1. The largest integer in the set is 13.
2. The arithmetic mean of the set is zero.
(2) We know the mean of the set is 0 but nothing about the distribution of the numbers. INSUFF.
(1) AND (2) tell us that the largest integer is 13 and the mean is 0. So all the remaining 9 numbers have to be < 13. I have the feeling that we could answer this question now, even though I'm not able to provide a clear solution.
I would gamble C, but definitely I need a better explanation from someone out there!
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ISNASHI
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- shashank.ism
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1/2 n +13 =0 --> n = -26harsh.champ wrote:One number, n, is selected at random from a set of 10 integers. What is the probability that ½ n + 13 = 0 ?
1. The largest integer in the set is 13.
2. The arithmetic mean of the set is zero.
St. 1 is insufficient. We don't know anything about what exactly other numbers are apart from numbers<13
St. 2 again insufficient. arithematic mean of set is zero ...a lot of combinations can do this .....by "a lot" i mean infinite.
combined: here also a lot of combination can make the arithematic mean 0 as we have a whole lot of no (-infinity,13)
so insufficient
I will go with E
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- shashank.ism
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I think cunazza you are going right way but for "combined" how could u say that friendcunazza wrote:(1) We know that the largest integer of the set is 13 but we know nothing about the lowest number, which could be up to - infinity. INSUFF.harsh.champ wrote:One number, n, is selected at random from a set of 10 integers. What is the probability that ½ n + 13 = 0 ?
1. The largest integer in the set is 13.
2. The arithmetic mean of the set is zero.
(2) We know the mean of the set is 0 but nothing about the distribution of the numbers. INSUFF.
(1) AND (2) tell us that the largest integer is 13 and the mean is 0. So all the remaining 9 numbers have to be < 13. I have the feeling that we could answer this question now, even though I'm not able to provide a clear solution.
I would gamble C, but definitely I need a better explanation from someone out there!
I wanna show u some combinations...
1,2,3,4,13,-13,-4,-3,-2,-1
2,3,4,5,13,-13,-5,-4,-3,-2
1,2,3,4,5,6,7,8,9,10,13,-68
......................................
......................................and so on
so there could be a lot of such combination which could be formed..please correct me if I m wrong..
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You are perfectly right, it's such a silly mistake I did. If I read it again now it's pretty obvious what you say.
I was timing myself and I was already over 1 minute when I came to analyze combined (1) and (2) so I did speed up my logic too much...
Your answer is correct.
I was timing myself and I was already over 1 minute when I came to analyze combined (1) and (2) so I did speed up my logic too much...
Your answer is correct.
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I appreciate you cunazza that you are using stop watch, a new tool by BTG moderators to solve problem in time...cunazza wrote:You are perfectly right, it's such a silly mistake I did. If I read it again now it's pretty obvious what you say.
I was timing myself and I was already over 1 minute when I came to analyze combined (1) and (2) so I did speed up my logic too much...
Your answer is correct.
Well I think you should give 2 min time for these problems.. And if ur taking a few seconds more than that, then also it s mangeable ..as there are lots of questions which you solve in few seconds only as your mind is very active that time....Hope I m correct..
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