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In a class of 25 students, 10 have less than 6 marbles [#permalink]
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23 Jan 2018, 15:02
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In a class of 25 students, 10 have less than 6 marbles, 10 have more than 7 marbles, 4 have more than 8 marbles. How many students have more than 5 but less than 9 marbles? a) 10 b) 11 c) 12 d) 13 e) none of these Need an effective method to work out these kinds of questions quickly. it is also requested to upload similar type of questions. thanks.
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Last edited by chetan2u on 23 Jan 2018, 17:07, edited 1 time in total.
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Re: In a class of 25 students, 10 have less than 6 marbles [#permalink]
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23 Jan 2018, 17:10
selim wrote: In a class of 25 students, 10 have less than 6 marbles, 10 have more than 7 marbles, 4 have more than 8 marbles. How many students have more than 5 but less than 9 marbles?
a) 10 b) 11 c) 12 d) 13 e) none of these
Need an effective method to work out these kinds of questions quickly. it is also requested to upload similar type of questions. thanks. You are looking for more than 5 and less than 9, meaning for students with 6,7 or 8 marbles.. 10 have less than 6, means they have 5 or less.. So 2510=15 have more than 5... Now 4 have more than 8, so they have 9, 10 or more.. So those with more than 5 but less than 9 =154=11 B
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Re: In a class of 25 students, 10 have less than 6 marbles [#permalink]
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25 Jan 2018, 09:58
chetan2u wrote: selim wrote: In a class of 25 students, 10 have less than 6 marbles, 10 have more than 7 marbles, 4 have more than 8 marbles. How many students have more than 5 but less than 9 marbles?
a) 10 b) 11 c) 12 d) 13 e) none of these
Need an effective method to work out these kinds of questions quickly. it is also requested to upload similar type of questions. thanks. You are looking for more than 5 and less than 9, meaning for students with 6,7 or 8 marbles.. 10 have less than 6, means they have 5 or less.. So 2510=15 have more than 5... Now 4 have more than 8, so they have 9, 10 or more.. So those with more than 5 but less than 9 =154=11 B Hi... Question stem also given 10 has more than 7 marbles so, how we conclude that it has exactly 8 marbles??? It might be 8 9 10..... Sent from my BNDAL10 using GMAT Club Forum mobile app



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In a class of 25 students, 10 have less than 6 marbles [#permalink]
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25 Jan 2018, 11:00
viv007 wrote: chetan2u wrote: selim wrote: In a class of 25 students, 10 have less than 6 marbles, 10 have more than 7 marbles, 4 have more than 8 marbles. How many students have more than 5 but less than 9 marbles?
a) 10 b) 11 c) 12 d) 13 e) none of these
Need an effective method to work out these kinds of questions quickly. it is also requested to upload similar type of questions. thanks. You are looking for more than 5 and less than 9, meaning for students with 6,7 or 8 marbles.. 10 have less than 6, means they have 5 or less.. So 2510=15 have more than 5... Now 4 have more than 8, so they have 9, 10 or more.. So those with more than 5 but less than 9 =154=11 B Hi... Question stem also given 10 has more than 7 marbles so, how we conclude that it has exactly 8 marbles??? It might be 8 9 10..... Sent from my BNDAL10 using GMAT Club Forum mobile appOut of the total 25 students, if 4 students definitely have more than 8 marbles(9,10....) and 10 students have less then 6 marbles(0,1,2,3,4,5), since we have been asked to find the total number of students who have between 5 and 9. The remaining 11(25410) students will have between 5 and 9 marbles for sure! Hope that clears your confusion!
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Re: In a class of 25 students, 10 have less than 6 marbles [#permalink]
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26 Jan 2018, 09:45
selim wrote: In a class of 25 students, 10 have less than 6 marbles, 10 have more than 7 marbles, 4 have more than 8 marbles. How many students have more than 5 but less than 9 marbles?
a) 10 b) 11 c) 12 d) 13 e) none of these We need to determine the number of students who have exactly 6, 7, or 8 marbles. Since 10 students have more than 7 marbles, and 4 have more than 8 marbles, it must mean 10  4 = 6 have exactly 8 marbles. Furthermore, since 10 students have more than 7 marbles and 10 have less than 6 marbles, it must mean 25  10  10 = 5 students have 6 or 7 marbles.Thus, the number of students who have more than 5 but less than 9 marbles is 6 + 5 = 11. Answer: B
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Re: In a class of 25 students, 10 have less than 6 marbles
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