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.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
08 Sep 2009, 03:36
Kudos
Bookmarks
anybody know a shortcut to these problems. Ex: X/Y 100<x<200 Y is even (or odd or some other restrictions)
How Xs are there that has terminating decimals (ie it ends).
How Xs are there that has terminating decimals (ie it ends).
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 Quantitative Questions 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!
11 Sep 2009, 11:11
Kudos
Bookmarks
A decimal terminates if the fully reduced fractional form of the number has nothing but factors of 2's and 5's (and 1's, of course) in the denominator.
For example, the following do NOT terminate: 2/19, 2/3, 1/17, 5/11, 7/15.
The following DO terminate: 1/20, 3/5, 373/500, 12/48 (because even though 48 has a factor of 3, in fully reduced form 12/48 = 1/4, which has only 2's in the denominator).
Why does this rule work? Because 2's and 5's are the components of 10, and our decimal system is base 10. Putting terminating decimals into fractional form can be easily done: the numerator consists of the digits after the decimal, the denominator of a power of 10 with the same number of zeros as the number of digits in the numerator.
For example:
0.123 = 123/1000 (3 digits after decimal)
0.45809 = 45,809/100,000 (5 digits after decimal)
0.7 = 7/10
So if you are asked whether x/y terminates, it depends on whether factors in x cancel all (any) non-2 or non-5 factors of y from the denominator.
For example, the following do NOT terminate: 2/19, 2/3, 1/17, 5/11, 7/15.
The following DO terminate: 1/20, 3/5, 373/500, 12/48 (because even though 48 has a factor of 3, in fully reduced form 12/48 = 1/4, which has only 2's in the denominator).
Why does this rule work? Because 2's and 5's are the components of 10, and our decimal system is base 10. Putting terminating decimals into fractional form can be easily done: the numerator consists of the digits after the decimal, the denominator of a power of 10 with the same number of zeros as the number of digits in the numerator.
For example:
0.123 = 123/1000 (3 digits after decimal)
0.45809 = 45,809/100,000 (5 digits after decimal)
0.7 = 7/10
So if you are asked whether x/y terminates, it depends on whether factors in x cancel all (any) non-2 or non-5 factors of y from the denominator.
11 Sep 2009, 17:36
Kudos
Bookmarks
well..tats a nice explanation..thankss
