GRE Prep 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.
[x] is the greatest integer less than or equal x, what is the value of
[#permalink]
15 Mar 2021, 10:30
15 Mar 2021, 10:30
1
Expert Reply
1
Bookmarks
00:00
Question Stats:
81% (01:03) correct
18% (00:45) wrong based on 33 sessions
Hide Show timer Statistics
\([x]\) is the greatest integer less than or equal \(x\), what is the value of \([√30]+[√40]+[√50]?\)
\(A. 12\)
\(B. 15\)
\(C. 16\)
\(D. 18\)
\(E. 20\)
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
\(A. 12\)
\(B. 15\)
\(C. 16\)
\(D. 18\)
\(E. 20\)
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: [x] is the greatest integer less than or equal x, what is the value of
[#permalink]
15 Mar 2021, 10:33
15 Mar 2021, 10:33
Carcass wrote:
\([x]\) is the greatest integer less than or equal \(x\), what is the value of \([√30]+[√40]+[√50]?\)
\(A. 12\)
\(B. 15\)
\(C. 16\)
\(D. 18\)
\(E. 20\)
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
\(A. 12\)
\(B. 15\)
\(C. 16\)
\(D. 18\)
\(E. 20\)
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITION
GRE - Math Book
GIVEN: [x] is the greatest integer less than or equal x
For example, [3.2] = 3, since 3 is the greatest integer that is less than (or equal) to 3.2
Likewise, [8.7] = 8, since 8 is the greatest integer that is less than (or equal to) 8.7
Now onto the question....
√25 = 5
√36 = 6
√49= 7
√64 = 8
Since √30 is BETWEEN √25 (aka 5) and √36 (aka 6), we know that √30 = 5.something
So, [√30] = 5
Since √40 is BETWEEN √36 (aka 6) and √49 (aka 6), we know that √40 = 6.something
So, [√40] = 6
Since √50 is BETWEEN √49 (aka 7) and √64 (aka 8), we know that √50 = 7.something
So, [√50] = 7
So, [√30]+[√40]+[√50] = 5 + 6 + 7 = 18
Answer: D
Cheers,
Brent
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Given Kudos: 172
Location: India
WE:Education (Education)
Re: [x] is the greatest integer less than or equal x, what is the value of
[#permalink]
15 Mar 2021, 23:27
15 Mar 2021, 23:27
Carcass wrote:
\([x]\) is the greatest integer less than or equal \(x\), what is the value of \([√30]+[√40]+[√50]?\)
\(A. 12\)
\(B. 15\)
\(C. 16\)
\(D. 18\)
\(E. 20\)
\(A. 12\)
\(B. 15\)
\(C. 16\)
\(D. 18\)
\(E. 20\)
\(5 ≤ \sqrt{30}\)
\(6 ≤ \sqrt{40}\)
\(7 ≤ \sqrt{50}\)
So, \(x = 5 + 6 + 7 = 18\)
Hence, option D
