GMAT Changed on April 16th - Read about the latest changes here

It is currently 23 Apr 2018, 12:22

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

In multiplication of the two digit numbers wx and cx, where w, x, and

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 44635
In multiplication of the two digit numbers wx and cx, where w, x, and [#permalink]

Show Tags

New post 11 Apr 2018, 09:09
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

54% (02:58) correct 46% (03:50) wrong based on 48 sessions

HideShow timer Statistics

In multiplication of the two digit positive numbers wx and cx, where w, x, and c are unique non-zero digits, the product is a three digit number. What is w + c - x?

(1) The three digits of the product are all the same and different from w, c and x.
(2) x and w + c are odd numbers.
[Reveal] Spoiler: OA

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

2 KUDOS received
Intern
Intern
User avatar
B
Joined: 04 Apr 2018
Posts: 21
GMAT ToolKit User
Re: In multiplication of the two digit numbers wx and cx, where w, x, and [#permalink]

Show Tags

New post 11 Apr 2018, 09:49
2
This post received
KUDOS
1
This post was
BOOKMARKED
Given : wx*cx = _ _ _ . Asked is w+c-x.

(1). If three digits of the product are all the same, then the product has only 9 possibilities which are :
(111, 222, 333, 444, .....................,888,999).
Now, we already know that 111= 37*3, hence all the possibilities can be re-written as follows:
(3*37 , 6*37 , 9*37 ,.....................,24*37,27*37)
Only the last possibility matches the given sets of conditions. Hence 27*37=999, because in this case ten's place is the same digit for both 27 as well as 37. So, w+c-x = 2+3-7 = -4 (Easily deduced). Hence SUFFICIENT !

(2). This mentions that x and w + c are both odd numbers. There are many possibilities.
We know only ODD+EVEN=ODD. So,either of (w,c) are (odd,even) or (even,odd). And x =ODD.
Case1. Let's say for one possibility, x=1; w=2; c=3 . This also satisfies the inital given condition that multiplication of the two digit numbers gives 3 digited product. Hence, So, w+c-x = 2+3-1 = 4.
Case2. Now for another possibility, say x=3; w=1; c=2. This also satisfies the inital given condition that multiplication of the two digit numbers gives 3 digited product. Hence, So, w+c-x = 1+2-3 = 0.
(There could be many other cases too but we can conclude from 2 cases only.)
So both the case gives a different answer, hence we cannot arrive at a unique solution from (2). Hence INSUFFICIENT !

So, the final answer to the question should be option A.
Manager
Manager
avatar
B
Joined: 02 Oct 2017
Posts: 60
Re: In multiplication of the two digit numbers wx and cx, where w, x, and [#permalink]

Show Tags

New post 22 Apr 2018, 18:33
I) Number could be 111,222,....999
111 has factors as 37*3
222 has 37*6
...
...
999=37*27 only 999 has same digit in its unit place.
Sufficient

II) can have multiple combination

So answer is A

Posted from my mobile device
Re: In multiplication of the two digit numbers wx and cx, where w, x, and   [#permalink] 22 Apr 2018, 18:33
Display posts from previous: Sort by

In multiplication of the two digit numbers wx and cx, where w, x, and

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.