Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Mar 2709:30 AM PDT
-10:30 AM PDT
Preparing for the GMAT? Avoid these 5 major mistakes that can lower your score and hurt your MBA dreams. In this expert panel discussion, 4 top GMAT coaches - GMAT Ninja, Jeff Miller from TTP, Rida Shafiq from eGMAT, and Chris Gentry from Manhattan Prep- Mar 27
10:00 AM PDT
-11:00 AM PDT
What happens after getting an MBA? Is it worth the investment? To find out, I interviewed 10 GMAT Club professionals who have completed their MBAs and built careers in consulting, finance, tech, and entrepreneurship. Their answers might surprise you! 
Mar 2911:30 AM EDT
-12:30 PM EDT
Learn how Keshav, a Chartered Accountant, scored an impressive 705 on GMAT in just 30 days with GMATWhiz's expert guidance. In this video, he shares preparation tips and strategies that worked for him, including the mock, time management, and more.
Mar 3005:30 AM PDT
-07:30 AM PDT
We know Strengthen and Weaken questions account for more than 50% of the CR questions on the GMAT. With CR becoming even more important on GMAT Focus, it's time you strengthen your weaknesses with an approach that improves your solving time and accuracy!
Mar 3011:00 AM IST
-01:00 PM IST
Attend this session to evaluate your current skill level, learn process skills, and solve through tough Arithmetic questions.
Mar 3110:00 AM EDT
-11:59 PM EDT
The Target Test Prep team has recently introduced TTP OnDemand GMAT, a 400-hour live masterclass video course created by Scott Woodbury-Stewart, founder and CEO of Target Test Prep.
Apr 0308:00 PM PDT
-09:00 PM PDT
Full-length FE mock with insightful analytics, weakness diagnosis, and video explanations!
02 Feb 2015, 07:25
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
95%
(hard)
Question Stats:
48% (02:20) correct
52%
(02:06)
wrong
based on 820
sessions
History
Date
Time
Result
Not Attempted Yet
02 Feb 2015, 12:51
Kudos
Bookmarks
Hi All,
The GMAT does not expect you to do an excessive amount of calculation to find the answer to a question, although you might be asked to do a reasonable amount of arithmetic in certain cases). When you're faced with this type of "calculation-based" question, if you can't find the hidden pattern or the "elegant" approach, you still have to opportunity to just do math. Be sure to note that there's a point at which you can STOP doing math though.....as long as you pay attention to the question that is ASKED.
Here, we're asked for the TENS DIGIT of 36^10.
We're clearly NOT going to calculate this entire product, but we can do some math and take advantage of how math "works"....
36^10 can be rewritten as....(36^4)(36^4)(36^2)
36^2 is a product that you should be able to calculate....
(36)(36) = 1296
Since the question is asking about the TENS DIGIT, anything to the "left" of the TENS DIGIT really doesn't matter, so we can SKIP THOSE DIGITS...
(36)(36) = (......96) a number that ends in 96.
36^4 = (36^2)(36^2)
We know that 36^2 ends in .....96, so we're really just multiplying....
(...96)(...96)
AND we're going to ignore every digit EXCEPT for the TENS and UNITS digits....(try doing the math; remember to stop working once you have those 2 digits figured out)....
(...96)(...96) = (......16)
Now we know that....
36^2 ends in ....96
36^4 ends in ....16
So we have a little more "math" to go....
(36^4)(36^4)(36^2) = (...16)(...16)(...96)
(...16)(...16) = ...56
(...56)(...96) = ...76
So, the TENS DIGIT = 7
Final Answer:
While this type of approach is not particularly elegant, if you're comfortable multiplying 2-digt numbers together, the work isn't that bad. It's also preferable to staring at the screen for 1-2 minutes and then blindly guessing.
GMAT assassins aren't born, they're made,
Rich
The GMAT does not expect you to do an excessive amount of calculation to find the answer to a question, although you might be asked to do a reasonable amount of arithmetic in certain cases). When you're faced with this type of "calculation-based" question, if you can't find the hidden pattern or the "elegant" approach, you still have to opportunity to just do math. Be sure to note that there's a point at which you can STOP doing math though.....as long as you pay attention to the question that is ASKED.
Here, we're asked for the TENS DIGIT of 36^10.
We're clearly NOT going to calculate this entire product, but we can do some math and take advantage of how math "works"....
36^10 can be rewritten as....(36^4)(36^4)(36^2)
36^2 is a product that you should be able to calculate....
(36)(36) = 1296
Since the question is asking about the TENS DIGIT, anything to the "left" of the TENS DIGIT really doesn't matter, so we can SKIP THOSE DIGITS...
(36)(36) = (......96) a number that ends in 96.
36^4 = (36^2)(36^2)
We know that 36^2 ends in .....96, so we're really just multiplying....
(...96)(...96)
AND we're going to ignore every digit EXCEPT for the TENS and UNITS digits....(try doing the math; remember to stop working once you have those 2 digits figured out)....
(...96)(...96) = (......16)
Now we know that....
36^2 ends in ....96
36^4 ends in ....16
So we have a little more "math" to go....
(36^4)(36^4)(36^2) = (...16)(...16)(...96)
(...16)(...16) = ...56
(...56)(...96) = ...76
So, the TENS DIGIT = 7
Final Answer:
While this type of approach is not particularly elegant, if you're comfortable multiplying 2-digt numbers together, the work isn't that bad. It's also preferable to staring at the screen for 1-2 minutes and then blindly guessing.
GMAT assassins aren't born, they're made,
Rich
02 Feb 2015, 14:35
Kudos
Bookmarks
Bunuel
What is the tens digit of 36^10?
A. 1
B. 3
C. 5
D. 7
E. 9
Kudos for a correct solution.
A. 1
B. 3
C. 5
D. 7
E. 9
Kudos for a correct solution.
36^10 = 6^20
(6^2)=6*6 = 36
(6^3)= 36*6 = .16
(6^4)= .16*6 = ..96
(6^5) = ..96*6 = ..76
(6^6) = ..76*6 = ...56
(6^7) = ....56*6 = ....36
If you see there is a pattern here in tens digits 3,1,9,7,5,3,1 and so on...
Continue the pattern up to 6^20 ( dont actually calculate full values) and answer is D: 7
Posted from my mobile device
