Last visit was: 18 Jul 2025, 15:31 It is currently 18 Jul 2025, 15:31
Close
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
Your Progress

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.
Close
Request Expert Reply
Confirm Cancel
Sub 505 Level|   Arithmetic|                        
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 18 Jul 2025
Posts: 102,619
Own Kudos:
Given Kudos: 98,235
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,619
Kudos: 742,543
 [22]
3
Kudos
Add Kudos
19
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 18 Jul 2025
Posts: 102,619
Own Kudos:
742,543
 [5]
Given Kudos: 98,235
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,619
Kudos: 742,543
 [5]
4
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
General Discussion
User avatar
WoundedTiger
Joined: 25 Apr 2012
Last visit: 25 Sep 2024
Posts: 523
Own Kudos:
2,482
 [2]
Given Kudos: 740
Location: India
GPA: 3.21
WE:Business Development (Other)
Products:
Posts: 523
Kudos: 2,482
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
AKG1593
Joined: 20 Dec 2013
Last visit: 30 Mar 2024
Posts: 182
Own Kudos:
312
 [1]
Given Kudos: 35
Location: India
Posts: 182
Kudos: 312
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Option B.
5.98~6 & 15.79~16
=>(sqrt){6 * (601+0.5)}/16
=>(sqrt)3600/16 = 60/4=15

Posted from my mobile device
User avatar
djanand
Joined: 27 Oct 2011
Last visit: 21 Jun 2014
Posts: 20
Own Kudos:
375
 [1]
Given Kudos: 25
Posts: 20
Kudos: 375
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Lets approximate 5.98 to 6, 601.5 to 600 & 15.79 to 16

so, \(\sqrt{\frac{6 * 600}{16}}\)

\(\sqrt{\frac{3600}{16}}\)

\(\frac{6*10}{4}\)

15. Option B
User avatar
Manofsteel
Joined: 03 Aug 2012
Last visit: 27 Jul 2019
Posts: 42
Own Kudos:
106
 [1]
Given Kudos: 28
Status:Never Give up!!!
Location: India
Concentration: Finance, General Management
Posts: 42
Kudos: 106
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Pretty Easy
Convert those decimals into integers as below:-
5.98 - 6
601.5 - 600
15.79 - 16

Then just plug in and solve you get 15 as the answer. Option (B)
User avatar
nutshell
Joined: 21 Mar 2011
Last visit: 04 Jul 2019
Posts: 95
Own Kudos:
295
 [2]
Given Kudos: 104
Status:GMATting
Concentration: Strategy, Technology
GMAT 1: 590 Q45 V27
GMAT 1: 590 Q45 V27
Posts: 95
Kudos: 295
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Approximate the following numbers:
5.98 ~ 6
601.5 ~ 600
15.79 ~ 16

\sqrt{6 * 600} = \sqrt{36 * 100} = 6 * 10
We know that \sqrt{16} = 4;

So, (6 * 10)/4 = 15;

Ans is (B)
User avatar
RSOHAL
User avatar
Ryerson (Ted Rogers) Thread Master
Joined: 27 Sep 2015
Last visit: 21 Feb 2016
Posts: 49
Own Kudos:
Given Kudos: 26
Location: Canada
GMAT 1: 410 Q33 V13
WE:Management Consulting (Computer Software)
GMAT 1: 410 Q33 V13
Posts: 49
Kudos: 662
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Using BALLPARKING

5.98 = 6
601.5 = 600
15.79 = 16

6 * 600/16 = 3600/16 sq root = 60/4 = 15

Answer B is correct.
avatar
mba2325
Joined: 13 Apr 2017
Last visit: 20 Jan 2023
Posts: 2
Given Kudos: 14
Location: United States
Concentration: General Management, Marketing
GPA: 3.9
Posts: 2
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
\(\sqrt{6 * 600 / 16}\\
= \sqrt{3600/16}\\
= \sqrt{225}\)
= 15
User avatar
CyberStein
Joined: 21 Jun 2017
Last visit: 02 Jun 2023
Posts: 60
Own Kudos:
Given Kudos: 3
Posts: 60
Kudos: 43
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Key word in this problem is "approximation"

1. 5.98(601.5) --> approximates --> 6(602) = 3612
2. 3612/16.00 = 225, which is a perfect root
3. √225 = 15

Answer is (B) 15
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 18 Jul 2025
Posts: 21,145
Own Kudos:
Given Kudos: 296
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 21,145
Kudos: 26,202
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
The Official Guide For GMAT® Quantitative Review, 2ND Edition

Of the following, the closest approximation to \(\sqrt{\frac{5.98(601.5)}{15.79}}\) is

(A) 5
(B) 15
(C) 20
(D) 25
(E) 225


We can approximate 5.98 to be 6, 601.5 to be 600, and 15.79 to be 16; thus, we have:

√[(6)(600)/(16)] = √(3600/16) = 60/4 = 15

Answer: B
User avatar
Kinshook
User avatar
Major Poster
Joined: 03 Jun 2019
Last visit: 18 Jul 2025
Posts: 5,702
Own Kudos:
Given Kudos: 161
Location: India
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Products:
GMAT 1: 690 Q50 V34
Posts: 5,702
Kudos: 5,236
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
The Official Guide For GMAT® Quantitative Review, 2ND Edition

Of the following, the closest approximation to \(\sqrt{\frac{5.98(601.5)}{15.79}}\) is

(A) 5
(B) 15
(C) 20
(D) 25
(E) 225

Problem Solving
Question: 97
Category: Arithmetic Estimation
Page: 74
Difficulty: 600

GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition - Quantitative Questions Project

Each week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution.

We'll be glad if you participate in development of this project:
1. Please provide your solutions to the questions;
2. Please vote for the best solutions by pressing Kudos button;
3. Please vote for the questions themselves by pressing Kudos button;
4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Thank you!

Of the following, the closest approximation to \(\sqrt{\frac{5.98(601.5)}{15.79}} = \sqrt{\frac{6*600}{16}}= \sqrt{3*3*5*5} = \sqrt{225}= 15\)

IMO B
avatar
sahuanamika
Joined: 22 May 2021
Last visit: 05 Oct 2021
Posts: 45
Own Kudos:
Given Kudos: 107
Posts: 45
Kudos: 20
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Approximation :

5.98~6,601.5~600 and 15.79~ 16
so we get √6∗600/16
60/4 = 15
Ans is B.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 37,454
Own Kudos:
Posts: 37,454
Kudos: 1,013
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderators:
Math Expert
102619 posts
PS Forum Moderator
698 posts