|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
![Jamboree and GMAT Club Contest: [N] denotes the greatest integer less](/forum/styles/gmatclub_light/imageset/icon_post_target_unread.svg "Jamboree and GMAT Club Contest: [N] denotes the greatest integer less"){kind=icon}
14 Nov 2015, 00:42
Kudos
Bookmarks
[N] denotes the greatest integer less than or equal to N. is [5N] = 0?
(1) [4N] = 0
(2) [6N] = 0
We are given that [N] denotes the greatest integer less than or equal to N. SO if N is 1.2 [N] = 1 or if N = 0.2 then [N] = 0 or if N = -0.2 then [N] = -1
so if [5N] = 0, 0<= 5N <1 or 0 <= N < 0.2. So N should be in this range.
(1) [4N] = 0
It means 0 <= 4N < 1 or 0 <= N < 0.25. This range is a superset of the range 0 <= N < 0.2. Therefore for some numbers, [5N] = 0 while for some other [5N] is not 0. Insufficient.
(2) [6N] = 0
It means 0 <= 6N < 1 or 0 <= N < 0.1666. This range is a subset of the range 0 <= N < 0.2. Therefore for all of the numbers in this range , [5N] = 0.Sufficient.
Ans. B
(1) [4N] = 0
(2) [6N] = 0
We are given that [N] denotes the greatest integer less than or equal to N. SO if N is 1.2 [N] = 1 or if N = 0.2 then [N] = 0 or if N = -0.2 then [N] = -1
so if [5N] = 0, 0<= 5N <1 or 0 <= N < 0.2. So N should be in this range.
(1) [4N] = 0
It means 0 <= 4N < 1 or 0 <= N < 0.25. This range is a superset of the range 0 <= N < 0.2. Therefore for some numbers, [5N] = 0 while for some other [5N] is not 0. Insufficient.
(2) [6N] = 0
It means 0 <= 6N < 1 or 0 <= N < 0.1666. This range is a subset of the range 0 <= N < 0.2. Therefore for all of the numbers in this range , [5N] = 0.Sufficient.
Ans. B
14 Nov 2015, 09:37
Kudos
Bookmarks
My answer B:
1) [4N] = 0 => 4N < 1 or N < 1/4. Therefore, 5N < 5/4 (greater than 1), so [5N] can be 0 or 1, hence insufficient
2) [6N] = 0 => 6N < 1 or N < 1/6. Therefore, 6N < 5/6 (less than 1). Because [6N] = 0 and N < 1, therefore, [5N] will be 0 (sufficient)
1) [4N] = 0 => 4N < 1 or N < 1/4. Therefore, 5N < 5/4 (greater than 1), so [5N] can be 0 or 1, hence insufficient
2) [6N] = 0 => 6N < 1 or N < 1/6. Therefore, 6N < 5/6 (less than 1). Because [6N] = 0 and N < 1, therefore, [5N] will be 0 (sufficient)
14 Nov 2015, 09:41
Kudos
Bookmarks
Bunuel
GMAT Club reserves the rights to modify the terms of this offer at any time. JAMBOBREE OFFICIAL SOLUTION:
As [N] denotes the greatest integer less than or equal to N, then for [5N] = 0, must be true that 0 ≤ 5N < 1, or whether 0 ≤ N < 0.2.
Statement 1: given [4N] = 0 --> 0 ≤ 4N < 1 --> 0 ≤ N < 0.25. Not sufficient.
Statement 2: given [6N] = 0 --> 0 ≤ 6N < 1 --> 0 ≤ N < 0.16666..... Sufficient.
Answer: B.
