GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 29 Jan 2020, 01:42 ### 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

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

#### 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

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor V
Joined: 16 Aug 2015
Posts: 8481
GMAT 1: 760 Q51 V42
GPA: 3.82
[x] is the greatest integer less than or equal x, what is the value of  [#permalink]

### Show Tags 00:00

Difficulty:   15% (low)

Question Stats: 81% (01:12) correct 19% (02:00) wrong based on 62 sessions

### HideShow timer Statistics

[Math Revolution GMAT math practice question]

$$[x]$$ is the greatest integer less than or equal $$x$$, what is the value of $$[√30]+[√40]+[√50]?$$

$$A. 12$$
$$B. 15$$
$$C. 16$$
$$D. 18$$
$$E. 20$$

_________________
Director  V
Joined: 04 Dec 2015
Posts: 727
Location: India
Concentration: Technology, Strategy
WE: Information Technology (Consulting)
[x] is the greatest integer less than or equal x, what is the value of  [#permalink]

### Show Tags

1
MathRevolution wrote:
[Math Revolution GMAT math practice question]

$$[x]$$ is the greatest integer less than or equal $$x$$, what is the value of $$[√30]+[√40]+[√50]?$$

$$A. 12$$
$$B. 15$$
$$C. 16$$
$$D. 18$$
$$E. 20$$

$$[√30]+[√40]+[√50]$$

$$[√30]$$ is between perfect squares $$25$$ and $$36$$. Square root of $$[√30]$$ is between $$5$$ and $$6$$.

Given $$[x]$$ is the greatest integer less than or equal $$x$$.

Therefore $$[√30] = 5$$

$$[√40]$$ is between perfect squares $$36$$ and $$49$$. Square root of $$[√40]$$ is between $$6$$ and $$7$$.

Therefore $$[√40] = 6$$

$$[√50]$$ is between perfect squares $$49$$ and $$64$$. Square root of $$[√50]$$ is between $$7$$ and $$8$$.

Therefore $$[√50] = 7$$

Hence $$[√30]+[√40]+[√50] = 5 + 6 + 7 = 18$$

GMAT Club Legend  V
Joined: 12 Sep 2015
Posts: 4235
Re: [x] is the greatest integer less than or equal x, what is the value of  [#permalink]

### Show Tags

Top Contributor
MathRevolution wrote:
[Math Revolution GMAT math practice question]

$$[x]$$ is the greatest integer less than or equal $$x$$, what is the value of $$[√30]+[√40]+[√50]?$$

$$A. 12$$
$$B. 15$$
$$C. 16$$
$$D. 18$$
$$E. 20$$

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

Cheers,
Brent
_________________
Math Revolution GMAT Instructor V
Joined: 16 Aug 2015
Posts: 8481
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: [x] is the greatest integer less than or equal x, what is the value of  [#permalink]

### Show Tags

=>

Since$$5 = √25 < √30 < √36 = 6$$, we have $$[√30] = 5$$.
Since $$6 = √36 < √40 < √49 = 7$$, we have $$[√40] = 6$$
Since $$7 = √49 < √50 < √64 = 8$$, we have $$[√50] = 7$$
Thus $$[√30]+[√40]+[√50] = 18.$$

_________________ Re: [x] is the greatest integer less than or equal x, what is the value of   [#permalink] 08 Nov 2018, 01:44
Display posts from previous: Sort by

# [x] is the greatest integer less than or equal x, what is the value of  