NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 00:17 It is currently 24 Apr 2024, 00:17
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

K is a two-digit number, if the sum of the tens and unit

User avatar
laxieqv
Director
Director
Joined: 24 Sep 2005
Posts: 833
Own Kudos [?]: 1479 [0]
Given Kudos: 0
Send PM
K is a two-digit number, if the sum of the tens and unit [#permalink] New post   05 Apr 2006, 08:53
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Hide Show timer Statistics
K is a two-digit number, if the sum of the tens and unit digits is 3 less than the product of the two digits. What is the value of K?



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
jcgoodchild
Manager
Manager
Joined: 09 Feb 2006
Posts: 50
Own Kudos [?]: 21 [0]
Given Kudos: 0
Location: New York, NY
Send PM
Re: K is a two-digit number, if the sum of the tens and unit [#permalink] New post   05 Apr 2006, 09:12
K is a two-digit number, if the sum of the tens and unit digits is 3 less than the product of the two digits. What is the value of K?

Let's set the tens digit as x and the units digit as y.

X+Y+3 = X*Y

I think that this then requires a slight bit of logic. X and Y need to be small because otherwise their product would be too great. After considering a couple of values, I can say that K is 33.

Is their a "foolproof" method to solving that equation? I realized that the equation could be set as x - xy + y = -3, but couldn't remember how to solve for x and y as a quadratic. Any thoughts?
User avatar
ccax
Manager
Manager
Joined: 20 Nov 2004
Posts: 50
Own Kudos [?]: 4 [0]
Given Kudos: 0
Send PM
Re: K is a two-digit number, if the sum of the tens and unit [#permalink] New post   05 Apr 2006, 09:34
K = 10A + B
A + B = A*B-3
A*B - A = B + 3
A*(B - 1) = B + 3
A = (B + 3)/(B - 1)

Then check the possible cases where both A and B
are integers. Start with B = 0 and end with B = 9.

This leads to 52, 33 and 25, so K cannot be determined.
User avatar
positive soul
Manager
Manager
Joined: 24 Oct 2005
Posts: 109
Own Kudos [?]: 317 [0]
Given Kudos: 0
Send PM
Re: K is a two-digit number, if the sum of the tens and unit [#permalink] New post   05 Apr 2006, 10:22
I agree...k cannot be determined without further information.
User avatar
Professor
Director
Director
Joined: 29 Dec 2005
Posts: 566
Own Kudos [?]: 176 [0]
Given Kudos: 0
Send PM
Re: K is a two-digit number, if the sum of the tens and unit [#permalink] New post   05 Apr 2006, 12:27
yah, there are more than one solution, Laxi.

laxieqv wrote:
K is a two-digit number, if the sum of the tens and unit digits is 3 less than the product of the two digits. What is the value of K?


how about -30 [10(-3) + 0], since 3 is -ve and 0 cannot be -ve or +ve.

sum = -3
product = 0
diff = -3

though it is only an additional one but i am not sure how correct it is?
User avatar
SunShine
Manager
Manager
Joined: 11 Nov 2005
Posts: 129
Own Kudos [?]: 54 [0]
Given Kudos: 0
Location: London
Send PM
Re: K is a two-digit number, if the sum of the tens and unit [#permalink] New post   06 Apr 2006, 13:52
when K has several values,
given in the choice one can select the right answer.



ccax wrote:
K = 10A + B
A + B = A*B-3
A*B - A = B + 3
A*(B - 1) = B + 3
A = (B + 3)/(B - 1)

Then check the possible cases where both A and B
are integers. Start with B = 0 and end with B = 9.

This leads to 52, 33 and 25, so K cannot be determined.




Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: K is a two-digit number, if the sum of the tens and unit [#permalink]
06 Apr 2006, 13:52
Moderators:
Bunuel
Math Expert
92883 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions