Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 46305

If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
24 Aug 2017, 23:48
Question Stats:
74% (00:41) correct 26% (00:43) wrong based on 76 sessions
HideShow timer Statistics



Director
Joined: 18 Aug 2016
Posts: 634
GMAT 1: 630 Q47 V29 GMAT 2: 740 Q51 V38

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
25 Aug 2017, 00:31
Bunuel wrote: If the perimeter of a triangle is 18, then the length of one of the sides CANNOT be
(A) 1 (B) 3 (C) 6 (D) 8 (E) 9 one side should always be less than the sum of other two sides if one side is 9 then the sum of other two sides will be 9..not possible E
_________________
We must try to achieve the best within us
Thanks Luckisnoexcuse



Manager
Joined: 14 Sep 2016
Posts: 149

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
25 Aug 2017, 02:57
We know that sum of any two sides of a triangle is greater than the side
hence if the length of a side is 9 then sum of the other two sides will 9 considering the perimeter as 18 under given condition the above scenario is not possible hence the answer is E



Intern
Joined: 11 Apr 2017
Posts: 38

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
26 Aug 2017, 13:45
one side should always be less than the sum of other two sides if one side is 9 then the sum of other two sides will be 9..not possible
E _________________
Thanks & all the best
(Like the below page on FB and show your support towards the upliftment of underprivileged)



Manager
Joined: 12 Mar 2015
Posts: 100
Concentration: Leadership, Finance
GPA: 3.9
WE: Information Technology (Computer Software)

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
26 Aug 2017, 14:02
Bunuel wrote: If the perimeter of a triangle is 18, then the length of one of the sides CANNOT be
(A) 1 (B) 3 (C) 6 (D) 8 (E) 9 I understand why E is the answer. But why not option A ? if one side is 1, the other two sides will be 8 and 9. These cannot be the sides of the triangle. Can someone please explain?



Intern
Joined: 23 Apr 2014
Posts: 4

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
27 Aug 2017, 01:55
hwgmat2015 wrote: Bunuel wrote: If the perimeter of a triangle is 18, then the length of one of the sides CANNOT be
(A) 1 (B) 3 (C) 6 (D) 8 (E) 9 I understand why E is the answer. But why not option A ? if one side is 1, the other two sides will be 8 and 9. These cannot be the sides of the triangle. Can someone please explain? Yes, why not A?the other two sides can be 10 and 7 as well.



VP
Status: Learning
Joined: 20 Dec 2015
Posts: 1161
Location: India
Concentration: Operations, Marketing
GRE 1: 314 Q157 V157
GPA: 3.4
WE: Manufacturing and Production (Manufacturing)

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
27 Aug 2017, 02:26
it can not be A let us take the case of an equilateral triangle perimeter is given to be 18 mm So each side would be 6 mm Now we have property of the triangle = ab<c<a+b Since each side is equal ab=0 a+b=12 so 0<c<12 but we know that perimeter is 18 so C<=6 I hope it is clear
_________________
Please give kudos if you found my answers useful



Manager
Joined: 11 Feb 2017
Posts: 202

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
27 Aug 2017, 03:49
Bunuel wrote: If the perimeter of a triangle is 18, then the length of one of the sides CANNOT be
(A) 1 (B) 3 (C) 6 (D) 8 (E) 9 I need help A) 1 should be greater than SUM OF OTHER 2 SIDES and Less than SUBTRACTION OF 2 SIDES So if one side is 1 other 2 will be x+y = 17 (well it satisfies that 3rd side should be less than addition of rest 2 so 1 is valid) But for subtraction? Lets take x= 9 , y =8 , SO 98 = 1 , HENCE IT SHOULD BE GREATER THAN 1 to satisfy second condition but its equal to 1 then IT MEANS 1 CANT BE INCLUDED PLEASE EXPLAIN



Math Expert
Joined: 02 Aug 2009
Posts: 5938

If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
27 Aug 2017, 04:18
rocko911 wrote: Bunuel wrote: If the perimeter of a triangle is 18, then the length of one of the sides CANNOT be
(A) 1 (B) 3 (C) 6 (D) 8 (E) 9 I need help A) 1 should be greater than SUM OF OTHER 2 SIDES and Less than SUBTRACTION OF 2 SIDES So if one side is 1 other 2 will be x+y = 17 (well it satisfies that 3rd side should be less than addition of rest 2 so 1 is valid) But for subtraction? Lets take x= 9 , y =8 , SO 98 = 1 , HENCE IT SHOULD BE GREATER THAN 1 to satisfy second condition but its equal to 1 then IT MEANS 1 CANT BE INCLUDED PLEASE EXPLAIN hi rocko911 and hwgmat2015.. the Q is looking for CANNOT be, which means it should not be possible..
now you are looking for a triangle with sides 1,8,9 but it can be 8.5,8.5 and 1... it is nowhere mentioned that sides are INTEGERS
_________________
Absolute modulus :http://gmatclub.com/forum/absolutemodulusabetterunderstanding210849.html#p1622372 Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
GMAT online Tutor



Manager
Joined: 11 Feb 2017
Posts: 202

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
27 Aug 2017, 04:31
chetan2u wrote: rocko911 wrote: Bunuel wrote: If the perimeter of a triangle is 18, then the length of one of the sides CANNOT be
(A) 1 (B) 3 (C) 6 (D) 8 (E) 9 I need help A) 1 should be greater than SUM OF OTHER 2 SIDES and Less than SUBTRACTION OF 2 SIDES So if one side is 1 other 2 will be x+y = 17 (well it satisfies that 3rd side should be less than addition of rest 2 so 1 is valid) But for subtraction? Lets take x= 9 , y =8 , SO 98 = 1 , HENCE IT SHOULD BE GREATER THAN 1 to satisfy second condition but its equal to 1 then IT MEANS 1 CANT BE INCLUDED PLEASE EXPLAIN hi rocko911 and hwgmat2015.. the Q is looking for CANNOT be, which means it should not be possible..
now you are looking for a triangle with sides 1,8,9 but it can be 8.5,8.5 and 1... it is nowhere mentioned that sides are INTEGERSyes indeed, But its also not mentioned that it cant be integers as well , so we need to take all posibilities, SO WHAT IF WE TAKE ONE SIDE AS 1 and other two be 9+8 , then it doesnt hold for subtraction rule becoz 98 = 1 and it should be greater than 1 AND IF ITS NOT SATISFYING THEN IT MEANS IT SHOULD "NOT" BE POSSIBLE just as everyone says 9 is



Math Expert
Joined: 02 Aug 2009
Posts: 5938

If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
27 Aug 2017, 04:37
rocko911 wrote: chetan2u wrote: hi rocko911 and hwgmat2015.. the Q is looking for CANNOT be, which means it should not be possible..
now you are looking for a triangle with sides 1,8,9 but it can be 8.5,8.5 and 1... it is nowhere mentioned that sides are INTEGERSyes indeed, But its also not mentioned that it cant be integers as well , so we need to take all posibilities, SO WHAT IF WE TAKE ONE SIDE AS 1 and other two be 9+8 , then it doesnt hold for subtraction rule becoz 98 = 1 and it should be greater than 1 AND IF ITS NOT SATISFYING THEN IT MEANS IT SHOULD "NOT" BE POSSIBLE just as everyone says 9 is hi.. CANNOT be means it is NOT possible under any circumstancesso for any value of other two sides if 1 is possible, then it will not come under CANNOT be. however 9 is NOT possible under any circumstances so it is our answer for that matter 3 will not be possible if sides are 3, 7,10.. you will always have value for which each choice will not be possible.. hope it helped
_________________
Absolute modulus :http://gmatclub.com/forum/absolutemodulusabetterunderstanding210849.html#p1622372 Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
GMAT online Tutor



Senior Manager
Status: You have to have the darkness for the dawn to come
Joined: 09 Nov 2012
Posts: 315
Daboo: Sonu
GMAT 1: 590 Q49 V20 GMAT 2: 730 Q50 V38

Re: If the perimeter of a triangle is 18, then the length of one of the [#permalink]
Show Tags
27 Aug 2017, 05:40
Bunuel wrote: If the perimeter of a triangle is 18, then the length of one of the sides CANNOT be
(A) 1 (B) 3 (C) 6 (D) 8 (E) 9 Here E must be the answer. as we know the sum of two sides must be greater than the third side. so if one side is 9 so sum of other two side will also be 9 and it violates rules mentioned earlier Hence E
_________________
You have to have the darkness for the dawn to come.
Give Kudos if you like my post




Re: If the perimeter of a triangle is 18, then the length of one of the
[#permalink]
27 Aug 2017, 05:40






