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Help me solve these problems

by manju_ej » Fri Jul 04, 2008 9:58 am
1) If xy+z=x(y+z), which of the following must be true?
(a) X=0 and z=0
(b) X=1 and y=1
(c) y=1 and z=0
(d) x=1 or y=0
(e) x=1 or z=0

2) Score Intervals Number of Score
50-59 2
60-69 10
70-79 16
80-89 27
90-99 18
The table above shows the distribution of test scores for a group of management trainees.
Which score interval contain the median of the 73 scores?

(a) 60-69
(b) 70-79
(c) 80-89
(d) 90-99
(e) It cannot be determined from the information given
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by swdatta » Fri Jul 04, 2008 10:21 am
I think the answer to question 1 is e
xy+z = x(y+z)
xy+z = xy+xz
z = xz
so x=1 or z=0

Answer for question 2 is C.
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Re: Help me solve these problems

by manju_ej » Fri Jul 04, 2008 11:55 am
manju_ej wrote:1) If xy+z=x(y+z), which of the following must be true?
(a) X=0 and z=0
(b) X=1 and y=1
(c) y=1 and z=0
(d) x=1 or y=0
(e) x=1 or z=0

2) Score Intervals Number of Score
50-59 2
60-69 10
70-79 16
80-89 27
90-99 18
The table above shows the distribution of test scores for a group of management trainees.
Which score interval contain the median of the 73 scores?

(a) 60-69
(b) 70-79
(c) 80-89
(d) 90-99
(e) It cannot be determined from the information given
Kindly explain in detail
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by sibbineni » Fri Jul 04, 2008 12:06 pm
1) If xy+z=x(y+z), which of the following must be true?
(a) X=0 and z=0
(b) X=1 and y=1
(c) y=1 and z=0
(d) x=1 or y=0
(e) x=1 or z=0

xy+z=xy+zx
=>xy+z-xy-zx=0
=>z-zx=0
=>z(1-x)=0

z=0 or (1-x)=0

so z=0 or x=1

IMO E

ONE QUESTION PER POST PLEASE
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by rs2010 » Fri Jul 04, 2008 7:54 pm
For second question I feel answer should be E.
Unless you specify the numbers you can not say anything about median.
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by userdce » Sat Jul 05, 2008 9:23 am
Second question's answer is C ?
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by Mahalo » Sat Jul 05, 2008 9:24 pm
II question : answer is C.

If there are 73 items, then 37th item (when arranged in ascending order) will show the median value.

upto 79, there are 2+10+16 = 28 items.

The 37th item will be in the range of 80-89 since there are 27 items in that range.
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by Abdulla » Sat Dec 13, 2008 7:14 pm
Mahalo wrote:II question : answer is C.

If there are 73 items, then 37th item (when arranged in ascending order) will show the median value.

upto 79, there are 2+10+16 = 28 items.

The 37th item will be in the range of 80-89 since there are 27 items in that range.

Could you explain it more in terms of scores not items as the question asks?
Abdulla
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Re: Help me solve these problems

by krazzy4 » Sun Dec 14, 2008 12:20 am
manju_ej wrote:
manju_ej wrote:1) If xy+z=x(y+z), which of the following must be true?
(a) X=0 and z=0
(b) X=1 and y=1
(c) y=1 and z=0
(d) x=1 or y=0
(e) x=1 or z=0

2) Score Intervals Number of Score
50-59 2
60-69 10
70-79 16
80-89 27
90-99 18
The table above shows the distribution of test scores for a group of management trainees.
Which score interval contain the median of the 73 scores?

(a) 60-69
(b) 70-79
(c) 80-89
(d) 90-99
(e) It cannot be determined from the information given
Kindly explain in detail
total student-73
so median must be unique. and 36th.to get this no.of students we must need the help of the range 80-89,because

only 28 students are below the median and hence those ranges are not valid.

only 18 students are above the median value and hence unvalid.

so the median must be in 80-89 score range.

hence C
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by cramya » Sun Dec 14, 2008 12:31 am
Could you explain it more in terms of scores not items as the question asks?
2)

The ranges given are sorted. If they were not then we must sort it first if not it could lead to misleading answers

Median is the middle number if the number of terms is odd after arranging the items in ascending order Here number of terms = 73 (i.e. if u add the numbers(freqencies) in the ranges provided).

If the number of terms is even then its the average of middle 2 terms after arranging the items in ascending order

Median can also be defined as the value that exists in the set for which there are as many numbers greater than it and as many values lesser than it.

Coming to the problem:

number of terms =73 median will be the 37th item. Like one of the users mentioned above the 37 th score will fall in the range 80-89 and hence the median will be in this range.


ScoreIntervals NumberofScore Total
50-59 2 Total 2
60-69 10 Total 12
70-79 16 Total 28
80-89 27 Total 55
90-99 18


The 37th item will fall in the 55 total which is in 80-89 range therefore the median will be in this range.We dont need to look at any scores as no values are given. We only need ot look at ranges since the answer choices are in ranges

Choose C)

Hope this helps!
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by KICKGMATASS123 » Fri May 29, 2009 11:02 am
cramya wrote:
Could you explain it more in terms of scores not items as the question asks?
2)

The ranges given are sorted. If they were not then we must sort it first if not it could lead to misleading answers

Median is the middle number if the number of terms is odd after arranging the items in ascending order Here number of terms = 73 (i.e. if u add the numbers(freqencies) in the ranges provided).

If the number of terms is even then its the average of middle 2 terms after arranging the items in ascending order

Median can also be defined as the value that exists in the set for which there are as many numbers greater than it and as many values lesser than it.

Coming to the problem:

number of terms =73 median will be the 37th item. Like one of the users mentioned above the 37 th score will fall in the range 80-89 and hence the median will be in this range.


ScoreIntervals NumberofScore Total
50-59 2 Total 2
60-69 10 Total 12
70-79 16 Total 28
80-89 27 Total 55
90-99 18


The 37th item will fall in the 55 total which is in 80-89 range therefore the median will be in this range.We dont need to look at any scores as no values are given. We only need ot look at ranges since the answer choices are in ranges

Choose C)


Hope this helps!

I fail to understand how u get 37..
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by kanha81 » Fri May 29, 2009 11:29 am
Same here! I don't understand the explanation provided for the 2nd question.

Can someone in the forum please elaborate in more simpler terms. Sorry :(
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by squishles10 » Sun May 31, 2009 1:14 pm
2+10+16+27+18=73 tests taken. Half the scores (36) are above the middle, and half the score are below the middle(another 36) so we're looking for score #37(the one that IS the middle) . (36+1+36=73)

Now go back and look at the distribution:

50-59 are below the middle score, so 36-2 leaves 34.
60-69 includes 10 scores, so 34-10 leaves 24 scores.
70-79 includes 16 scores, now 24-16, leaving 8 scores.
80-89 includes 27 scores, but there are only 8 below the average so the middle score has to be in this group.
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