geometry

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geometry

by Gurpinder » Tue Sep 14, 2010 10:59 am
in isosceles triangle MNO, the length of MN is 5. What is the perimeter of the triangle?
(1) the length of MO is 11.
(2) NO is longer than MN


please explain!!
Last edited by Gurpinder on Tue Sep 14, 2010 3:52 pm, edited 1 time in total.
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Source: — Data Sufficiency |

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by beatthegmatinsept » Tue Sep 14, 2010 12:26 pm
Can you check choice a? MNO = 11? Did you mean NO = 11?
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by goyalsau » Tue Sep 14, 2010 2:56 pm
Gurpinder wrote:in isosceles triangle MNO, the length of MN is 5. What is the perimeter of the triangle?
(1) the length of MNO is 11.
(2) NO is longer than MN


please explain!!
my answer is E,
what's the official answer?

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by Gurpinder » Tue Sep 14, 2010 3:52 pm
sorry guys, i've made the correction.

thx
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by selango » Tue Sep 14, 2010 8:58 pm
MN=5

stmt2,

NO is longer than MN.

-->MO and MN are of equal length.MO=5

We still don't know value of NO.

Isuff

stmt2,

Length of MO=11


-->NO and MN are of equal length.

Actually this contradicts stmt2.

Hey gurpinder I think its length of NO is 11.

MO and MN are of equal length.MO=5

Perimtere of triangle=MN+MO+NO=5+5+11=21

Suff

Pick A
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by Gurpinder » Tue Sep 14, 2010 9:02 pm
selango wrote:MN=5

Hey gurpinder I think its length of NO is 11.
hey....

no man MO = 11.

i just checked. this question is from Princeton book pg. 157
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by beatthegmatinsept » Tue Sep 14, 2010 9:09 pm
Gurpinder wrote:in isosceles triangle MNO, the length of MN is 5. What is the perimeter of the triangle?
(1) the length of MO is 11.
(2) NO is longer than MN


please explain!!
A is enough.
Rules of sides of a triangle:
difference of 2 sides (11-5 = 6) is always smaller than the 3rd side. So you know 3rd side cant be equal to MN (=5), so it must be equal to 11, since its an isosceles triangle. Perimeter = 11 + 11 + 5 = 27.
A Sufficient.

B doesn't give you enough information. So, B Insufficient.
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by goyalsau » Tue Sep 14, 2010 10:38 pm
beatthegmatinsept wrote:
Gurpinder wrote:in isosceles triangle MNO, the length of MN is 5. What is the perimeter of the triangle?
(1) the length of MO is 11.
(2) NO is longer than MN


please explain!!
A is enough.
Rules of sides of a triangle:
difference of 2 sides (11-5 = 6) is always smaller than the 3rd side. So you know 3rd side cant be equal to MN (=5), so it must be equal to 11, since its an isosceles triangle. Perimeter = 11 + 11 + 5 = 27.
A Sufficient.

B doesn't give you enough information. So, B Insufficient.
Good work beatthegmatinsept .
Can you please share that why thought firstly when you saw the question that it can be wrong.
I think that is also a very important concept.

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by goyalsau » Tue Sep 14, 2010 10:45 pm
goyalsau wrote:
Gurpinder wrote:in isosceles triangle MNO, the length of MN is 5. What is the perimeter of the triangle?
(1) the length of MNO is 11.
(2) NO is longer than MN


please explain!!
my answer is E,
what's the official answer?
Guys i Just wana ask is this the right answer to this question...

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by beatthegmatinsept » Wed Sep 15, 2010 6:26 am
goyalsau wrote:
beatthegmatinsept wrote:
Gurpinder wrote:in isosceles triangle MNO, the length of MN is 5. What is the perimeter of the triangle?
(1) the length of MO is 11.
(2) NO is longer than MN


please explain!!
A is enough.
Rules of sides of a triangle:
difference of 2 sides (11-5 = 6) is always smaller than the 3rd side. So you know 3rd side cant be equal to MN (=5), so it must be equal to 11, since its an isosceles triangle. Perimeter = 11 + 11 + 5 = 27.
A Sufficient.

B doesn't give you enough information. So, B Insufficient.
Good work beatthegmatinsept .
Can you please share that why thought firstly when you saw the question that it can be wrong.
I think that is also a very important concept.
It said "the length of MNO is 11. "
I started to think of a circle, if MNO is an arc? Or if it meant MN or NO... Actually, I was also being plain lazy to not solve a problem that I wasn't sure of what it was saying :)
Being defeated is often only a temporary condition. Giving up is what makes it permanent.