Find all School-related info fast with the new School-Specific MBA Forum

It is currently 21 Oct 2014, 07:37

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Can anyone explain to me ?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 09 Jun 2010
Posts: 79
Followers: 1

Kudos [?]: 2 [0], given: 17

Can anyone explain to me ? [#permalink] New post 18 Jun 2010, 07:38
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (00:00) correct 0% (00:00) wrong based on 1 sessions
If S and T are positive integers such that S/t=64.12, which of the follwing could be the remainder when s is divided by T ?

A 2
B 4
c 8
D 20
E 45

the answer is E, But why ?

Of the three-digit integers greater than 700, how many have two digits that are equal to each other and the remaining different from the other two ?

A 90
B 82
C 80
D 45
E 36

The answer is C, again I dont know why ? so pleas someone help me out and I will very thankful
[Reveal] Spoiler: OA
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23351
Followers: 3604

Kudos [?]: 28710 [0], given: 2815

Re: Can anyone explain to me ? [#permalink] New post 18 Jun 2010, 07:53
Expert's post
If s and t are positive integer such that s/t=64.12, which of the following could be the remainder when s is divided by t?
(A) 2
(B) 4
(C) 8
(D) 20
(E) 45

We know that when we are told that "s divided by t gives remainder r" can be expressed by the following formula: s=qt+r, in or case q=64, --> s=64t+r, divide both parts by t --> \frac{s}{t}=64.12=64+\frac{r}{t} --> 0.12=\frac{r}{t}--> \frac{3}{25}=\frac{r}{t} so r must be the multiple of 3. Only answer multiple of 3 is 45.

Or: \frac{s}{t}=64\frac{12}{100}=64\frac{3}{25}, so if the divisor=t=25 then the remainder=r=3. Basically we get that divisor is a multiple of 25 and the remainder is a multiple of 3. Only answer multiple of 3 is 45.

Answer: E.

Of the three digits greater than 700, how many have two digits that are equal to each other and the remaining digit different from the other two
(A) 90
(B) 82
(C) 80
(D) 45
(E) 36

3-digit numbers more than 700 = 299;

Numbers with all distinct digits = 3*9*8=216 (first digit can take 3 values - 7, 8, 9; second digit can take 9 values and the third digit 8 values);

Numbers with all the same digits more than 700 = 3, (777, 888, 999);

{all} - {all distinct} - {all same} = {two equal} --> 299-216-3=80.

Answer: C.

Please post one question per topic.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Intern
Intern
User avatar
Affiliations: NYSSA
Joined: 07 Jun 2010
Posts: 35
Location: New York City
Schools: Wharton, Stanford, MIT, NYU, Columbia, LBS, Berkeley (MFE program)
WE 1: Senior Associate - Thomson Reuters
WE 2: Analyst - TIAA CREF
Followers: 0

Kudos [?]: 4 [0], given: 2

Re: Can anyone explain to me ? [#permalink] New post 18 Jun 2010, 10:26
^
For Q1. I had 3/25T=R... but I couldn't figure out what to do from here...

It maybe easier to rewrite it as T=R*25/3. Since R must be an integer, it must be divisible by 3.
Manager
Manager
avatar
Joined: 09 Jun 2010
Posts: 79
Followers: 1

Kudos [?]: 2 [0], given: 17

Re: Can anyone explain to me ? [#permalink] New post 30 Jun 2010, 16:30
I need someone to explain the questions with datialed but thanks for the help anyway
Intern
Intern
avatar
Joined: 21 Apr 2010
Posts: 31
GMAT 1: 710 Q48 V40
Followers: 0

Kudos [?]: 26 [0], given: 0

Re: Can anyone explain to me ? [#permalink] New post 01 Jul 2010, 12:11
xmagedo wrote:
I need someone to explain the questions with datialed but thanks for the help anyway


you know S/T= 64 + .12

.12= R/T R/T=12/100 -> R/T=3/25 -> 25R = 3T , because 25 does not have any factors of 3 in it that means that R must have a factor of 3 in it because 25 x R = a multiple of 3. Try plugging in real numbers if this seems fuzzy.

The second one is a combinators problem. The only way you can get the answer is by counting the possibilties.

999-700 = 299 total numbers

at this point you can find the number of ways where two equal digit occurs for 3 digit numbers or you can find number of ways that two equal digits do not occur subtract it from the total number of possibilitys

There are 3 possibilities for the first number 7,8,9
There are 10 possibilities for the second 0-9
There are 10 possibilities for the third 0-9

A 3 digit number can be 1 of 3 things in this case. It can have no equal digits, It can have 1 equal digit or it can have 2 equal digits. For example a number can be 707, 770, or 777. The possibility of having only 2 equal digit is as Bunuel mentioned "

{all} - {all distinct} - {all same} = {two equal}}

All = 299
All Distinct = 3x9x8 ( 3 for the first choice, the pool of choices is reduced by 1 for the second number, the pool is reduced again for the third - because we want DISTINCT numbers.

All same = 3 There only 3 numbers greater than 700 that are all the same here: they are 777,888, and 999

so - > 299-216-3=80.

You can solve this problem another way by finding directly how many numbers have 2 equal digits but its much harder.
_________________

Ps. Kudos are always welcomed ; )

Manager
Manager
User avatar
Joined: 22 Oct 2009
Posts: 242
GMAT 1: 760 Q49 V44
GPA: 3.88
Followers: 6

Kudos [?]: 63 [0], given: 1

Re: Can anyone explain to me ? [#permalink] New post 03 Jul 2010, 11:33
xmagedo wrote:
I need someone to explain the questions with datialed but thanks for the help anyway


Could you be more specific as to what you don't understand? Which question? Where did Bunuel's answer lose you?
Re: Can anyone explain to me ?   [#permalink] 03 Jul 2010, 11:33
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic can anyone solve this problem and explain me tparanidharan 12 24 Apr 2011, 10:44
1 CAN ANYONE EXPLAIN IT TO ME PLEASE fatihaysu 12 08 Sep 2010, 09:43
A meatman weighed some pieces of beef and recorded the mohdnisar2009 1 28 Oct 2009, 20:45
can anyone explain me in details. mohdnisar2009 2 28 Oct 2009, 20:49
Display posts from previous: Sort by

Can anyone explain to me ?

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.