Last visit was: 13 Jul 2024, 12:17 It is currently 13 Jul 2024, 12:17
Toolkit
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.

# 31/125 =

SORT BY:
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 94339
Own Kudos [?]: 640504 [29]
Given Kudos: 85005
Math Expert
Joined: 02 Sep 2009
Posts: 94339
Own Kudos [?]: 640504 [50]
Given Kudos: 85005
Manager
Joined: 11 Jan 2014
Posts: 78
Own Kudos [?]: 413 [9]
Given Kudos: 11
Concentration: Finance, Statistics
GMAT Date: 03-04-2014
GPA: 3.77
WE:Analyst (Retail Banking)
General Discussion
Manager
Joined: 04 Oct 2013
Posts: 127
Own Kudos [?]: 304 [3]
Given Kudos: 55
Location: India
GMAT Date: 05-23-2015
GPA: 3.45
2
Kudos
1
Bookmarks
$$\frac{31}{125} =$$

(A) 0.248
(B) 0.252
(C) 0.284
(D) 0.312
(E) 0.320

$$\frac{31}{125} = \frac{31*8}{125*8} = \frac{248}{1000} = 0.248$$

Intern
Joined: 03 Feb 2015
Posts: 6
Own Kudos [?]: 5 [0]
Given Kudos: 16
Concentration: Entrepreneurship, Finance
GMAT Date: 07-31-2015
GMAT 1: 580 Q44 V26
GRE 1: Q159 V152
GPA: 3.59
125 can simply be written as 1000/8
multiply 8 with 31 to get 248
divide it by 1000 to get .248
simple one
Intern
Joined: 26 Feb 2016
Posts: 11
Own Kudos [?]: 1 [0]
Given Kudos: 26
Bunuel wrote:
SOLUTION

$$\frac{31}{125} =$$

(A) 0.248
(B) 0.252
(C) 0.284
(D) 0.312
(E) 0.320

$$\frac{31}{125} =\frac{31*8}{125*8} =\frac{248}{1000} =0.248$$.

why do you choose to times by 8?
Math Expert
Joined: 02 Sep 2009
Posts: 94339
Own Kudos [?]: 640504 [2]
Given Kudos: 85005
2
Kudos
sabxu1 wrote:
Bunuel wrote:
SOLUTION

$$\frac{31}{125} =$$

(A) 0.248
(B) 0.252
(C) 0.284
(D) 0.312
(E) 0.320

$$\frac{31}{125} =\frac{31*8}{125*8} =\frac{248}{1000} =0.248$$.

why do you choose to times by 8?

The options are in decimals. To transform a fraction to decimal the denominator must be some power of 10. 125*8 = 1000.
Intern
Joined: 26 Feb 2016
Posts: 11
Own Kudos [?]: 1 [0]
Given Kudos: 26
Bunuel wrote:
sabxu1 wrote:
Bunuel wrote:
SOLUTION

$$\frac{31}{125} =$$

(A) 0.248
(B) 0.252
(C) 0.284
(D) 0.312
(E) 0.320

$$\frac{31}{125} =\frac{31*8}{125*8} =\frac{248}{1000} =0.248$$.

why do you choose to times by 8?

The options are in decimals. To transform a fraction to decimal the denominator must be some power of 10. 125*8 = 1000.

do you times i by 8 because you want to get to an easy number such as 1000?
Math Expert
Joined: 02 Sep 2009
Posts: 94339
Own Kudos [?]: 640504 [0]
Given Kudos: 85005
sabxu1 wrote:
Bunuel wrote:
sabxu1 wrote:
why do you choose to times by 8?

The options are in decimals. To transform a fraction to decimal the denominator must be some power of 10. 125*8 = 1000.

do you times i by 8 because you want to get to an easy number such as 1000?

As I said, we multiply by 8 to get in the denominator some power of 10 to transform the fraction into the decimal easily.
SVP
Joined: 06 Nov 2014
Posts: 1793
Own Kudos [?]: 1378 [1]
Given Kudos: 23
1
Kudos
sabxu1 wrote:
Bunuel wrote:
SOLUTION

$$\frac{31}{125} =$$

(A) 0.248
(B) 0.252
(C) 0.284
(D) 0.312
(E) 0.320

$$\frac{31}{125} =\frac{31*8}{125*8} =\frac{248}{1000} =0.248$$.

why do you choose to times by 8?

Since the options are all in the decimal forms, we need to divide the numerator by denominator.
If we have a calculator, we can directly divide it. But since we are not allowed a calculator, we need to make our lives simpler.

Hence we try to bring denominator in a form by which the division becomes easier.
125 = 5^3
If we multiply 5^3 by 2^3, we get 10^3 or 1000 and then we can easily divide.

Board of Directors
Joined: 11 Jun 2011
Status:QA & VA Forum Moderator
Posts: 6049
Own Kudos [?]: 4763 [2]
Given Kudos: 463
Location: India
GPA: 3.5
2
Kudos
Bunuel wrote:
$$\frac{31}{125} =$$

(A) 0.248
(B) 0.252
(C) 0.284
(D) 0.312
(E) 0.320

$$\frac{31}{125}$$

$$~ \frac{31}{124}$$

$$=\frac{1}{4}$$

$$=0.25$$

Thus, answer will be (A) 0.248
Manager
Joined: 12 Jun 2016
Posts: 145
Own Kudos [?]: 232 [0]
Given Kudos: 151
Location: India
WE:Sales (Telecommunications)
In case someone is interested in a more detailed approach.

$$\frac{31}{125} = \frac{30}{125}+\frac{1}{125} \\ \\ = \frac{6}{25}+\frac{1}{125} \\ \\ = \frac{5}{25} + \frac{1}{25} + \frac{1}{125} \\ \\ = \frac{1}{5}+ \frac{1}{25} + \frac{1}{125}$$

$$= 0.2 + \frac{0.2}{5}+ \frac{1}{125} = 0.2 +0.04 + \frac{1}{125} = 0.24 + \frac{1}{125}$$

= a little over 0.24

= Option A
Board of Directors
Joined: 11 Jun 2011
Status:QA & VA Forum Moderator
Posts: 6049
Own Kudos [?]: 4763 [0]
Given Kudos: 463
Location: India
GPA: 3.5
Bunuel wrote:
The Official Guide For GMAT® Quantitative Review, 2ND Edition

$$\frac{31}{125} =$$

(A) 0.248
(B) 0.252
(C) 0.284
(D) 0.312
(E) 0.320

Problem Solving
Question: 58
Category: Arithmetic Operations on rational numbers
Page: 69
Difficulty: 500

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:
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!

$$\frac{31}{125}$$

Or, $$\frac{31}{124}=\frac{1}{4} = 0.25$$

Since we have approximated 125 as 124, 0.25 will be slightly less than 0.25 ie, 0.248, Answer must be (A)
Non-Human User
Joined: 09 Sep 2013
Posts: 33963
Own Kudos [?]: 851 [0]
Given Kudos: 0