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 1612:00 PM EDT
-11:59 PM EDT
You’re first to know: Save $200 on GMAT prep starting tomorrow, 4/13. Get 6 official practice tests and study with real questions. Be ready to save!
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.
01 Mar 2020, 17:16
Kudos
Bookmarks
If a, b, c, d and e are integers and p = 2^a3^b and q = 2^c3^d5^e, is p/q a terminating decimal?
(1) a > c
(2) b > d
For a fraction to have a terminating decimal, the numerator must be an integer and the denominator must be only powers of 2s and/or 5s. We have the fraction 2^a3^b/2^c3^d5^e. The numerator is okay, because we know it will be an integer. The denominator must be only powers of 2s and/or 5s, so we need to see if we can cancel the 3^d for the fraction to be terminating. The only way to get rid of the 3^d in the denominator would be for the power of 3^b in the numerator to be larger than 3^d in the denominator. When an integer raised to a power in the numerator is larger than the same integer raised to a power in the denominator, we can subtract/cancel the denominator. For instance, 2^4/2^3 is simply 2^1. Thus, we need to see if 3^b is greater than 3^d, so we need to ask: b>d?
So, back to the question.
1) Doesn't tell us anything about b>d. There is still a 3 in the denominator, so we won't be able to prove whether this is a terminating decimal or not. INSUFFICIENT
2) This is exactly what we are looking for. We know that b>d, so we know that the 3^d in the denominator will go away, thus leaving only powers of 2 and 5 in the denominator, making this fraction a terminating decimal. SUFFICIENT.
Answer (B).
(1) a > c
(2) b > d
For a fraction to have a terminating decimal, the numerator must be an integer and the denominator must be only powers of 2s and/or 5s. We have the fraction 2^a3^b/2^c3^d5^e. The numerator is okay, because we know it will be an integer. The denominator must be only powers of 2s and/or 5s, so we need to see if we can cancel the 3^d for the fraction to be terminating. The only way to get rid of the 3^d in the denominator would be for the power of 3^b in the numerator to be larger than 3^d in the denominator. When an integer raised to a power in the numerator is larger than the same integer raised to a power in the denominator, we can subtract/cancel the denominator. For instance, 2^4/2^3 is simply 2^1. Thus, we need to see if 3^b is greater than 3^d, so we need to ask: b>d?
So, back to the question.
1) Doesn't tell us anything about b>d. There is still a 3 in the denominator, so we won't be able to prove whether this is a terminating decimal or not. INSUFFICIENT
2) This is exactly what we are looking for. We know that b>d, so we know that the 3^d in the denominator will go away, thus leaving only powers of 2 and 5 in the denominator, making this fraction a terminating decimal. SUFFICIENT.
Answer (B).
13 Apr 2020, 04:55
Kudos
Bookmarks
13 Apr 2020, 05:46
Kudos
Bookmarks
ShivamoggaGaganhs
Hi
As far as 2s and 5s are concerned, it doesn’t matter what is the powers and how much power is in denominator as they will always lead to terminating decimal.
Now if c and e are NEGATIVE, the term would move up and become positive. For example. 1/(2^-3) will become 2^3.
