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 2212:30 AM EDT
-01:30 AM EDT
At one point, she believed GMAT wasn’t for her. After scoring 595, self-doubt crept in and she questioned her potential. But instead of quitting, she made the right strategic changes. The result? A remarkable comeback to 695. Check out how Saakshi did it.
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 2301:30 AM EDT
-02:30 AM EDT
Struggling with GMAT Verbal as a non-native speaker? Harsh improved his score from 595 to 695 in just 45 days—and scored a 99 %ile in Verbal (V88)! Learn how smart strategy, clarity, and guided prep helped him gain 100 points.
Apr 2308:00 PM PDT
-09:00 PM PDT
Video explanations + diagnosis of 10 weakest areas + 150+ short videos + study plan!
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.
Updated on: 20 May 2020, 05:12
Originally posted by ManishaPrepMinds on 20 May 2020, 00:22.
Last edited by ManishaPrepMinds on 20 May 2020, 05:12, edited 1 time in total.
Last edited by ManishaPrepMinds on 20 May 2020, 05:12, edited 1 time in total.
Kudos
Bookmarks
What’s the sum of even integers from 102 to 686?
Seems tedious? Let's find out!!
Let's consider the set {4,5,8,12, 20} can we find any pattern between the numbers in the above set? Not Really!
Let’s consider this set {2, 5, 8, 11, 14} can we Observe something ? Yes, we do!
Here the difference between any two consecutive numbers is 3 or the increment between any two consecutive numbers is Fixed.
Thus, all such sets where the difference between any two consecutive numbers is the same are defined as Evenly Spaced Sets.
Example: Set of consecutive Integers, Set of consecutive even integers, set of consecutive odd integers, multiples of 3...so on
Few facts about the Evenly spaced sets which are tested on GMAT:
[1) Mean of the set is always equal to the median of the set
2) Average of the first and last terms in the set is equal to mean of the set
3) Number of terms in the given set =({Last term – First term}/increament) +1
With these facts, we can very easily find the sum of all numbers in the given evenly spaced set!
Using, Sum = Mean * number of terms in the given set
Example : 2 + 4 + 6+8…………250
Given set is evenly Spaced set with the increment 2
(i) Let’s calculate the Mean of above set : (2 + 250)/2=126
(ii) Number of terms = {2,4, 6, ……250}
= {(250-2)/2 + 1}
=124+1
=125
Sum = Mean * number of terms in the given set
126*125
=15,750
Thus, the sum of even integers from 102 to 686:
Mean=(102+686)/2 =394
Number of terms={(686-102)/2 +1}=293
Sum=293*394=115442
Let’s solve GMAT Data Sufficiency question on the same facts:
If each term of Set S is defined as Sn=Sn–1+4, what is the median value of the set?
(1) S1 = 20.
(2) The arithmetic mean of set S is 40.
Inference from the question stem:
Sn=Sn–1+4
Sn−Sn–1=4.
Thus, Set S is evenly spaced set as the difference in any two consecutive terms in the set S is 4
Now Analyze Stat (1) alone:
1. S1 = 20
This just tells us that first term in the set is 20
Thus, stat (1) alone is not sufficient to find the answer to the given question
Analyze Stat (2) alone:
2. The arithmetic mean of set S is 40
For Evenly spaced sets Mean of the set is always equal to the median of the set
Median of the set S is 40
Thus, stat (2) alone is sufficient to answer the question
Hence, the answer is B
Cheers!
Manisha
PrepMinds Founder
Gmat Quant Expert
Seems tedious? Let's find out!!
Let's consider the set {4,5,8,12, 20} can we find any pattern between the numbers in the above set? Not Really!
Let’s consider this set {2, 5, 8, 11, 14} can we Observe something ? Yes, we do!
Here the difference between any two consecutive numbers is 3 or the increment between any two consecutive numbers is Fixed.
Thus, all such sets where the difference between any two consecutive numbers is the same are defined as Evenly Spaced Sets.
Example: Set of consecutive Integers, Set of consecutive even integers, set of consecutive odd integers, multiples of 3...so on
Few facts about the Evenly spaced sets which are tested on GMAT:
[1) Mean of the set is always equal to the median of the set
2) Average of the first and last terms in the set is equal to mean of the set
3) Number of terms in the given set =({Last term – First term}/increament) +1
With these facts, we can very easily find the sum of all numbers in the given evenly spaced set!
Using, Sum = Mean * number of terms in the given set
Example : 2 + 4 + 6+8…………250
Given set is evenly Spaced set with the increment 2
(i) Let’s calculate the Mean of above set : (2 + 250)/2=126
(ii) Number of terms = {2,4, 6, ……250}
= {(250-2)/2 + 1}
=124+1
=125
Sum = Mean * number of terms in the given set
126*125
=15,750
Thus, the sum of even integers from 102 to 686:
Mean=(102+686)/2 =394
Number of terms={(686-102)/2 +1}=293
Sum=293*394=115442
Let’s solve GMAT Data Sufficiency question on the same facts:
If each term of Set S is defined as Sn=Sn–1+4, what is the median value of the set?
(1) S1 = 20.
(2) The arithmetic mean of set S is 40.
Inference from the question stem:
Sn=Sn–1+4
Sn−Sn–1=4.
Thus, Set S is evenly spaced set as the difference in any two consecutive terms in the set S is 4
Now Analyze Stat (1) alone:
1. S1 = 20
This just tells us that first term in the set is 20
Thus, stat (1) alone is not sufficient to find the answer to the given question
Analyze Stat (2) alone:
2. The arithmetic mean of set S is 40
For Evenly spaced sets Mean of the set is always equal to the median of the set
Median of the set S is 40
Thus, stat (2) alone is sufficient to answer the question
Hence, the answer is B
Cheers!
Manisha
PrepMinds Founder
Gmat Quant Expert
20 May 2020, 01:37
Kudos
Bookmarks
What’s the sum of even integers from 102 to 686?
For those who, like me, try to solve the opening question but could not locate the answer in the rest of the post,
the answer is 115442.
For those who, like me, try to solve the opening question but could not locate the answer in the rest of the post,
the answer is 115442.
20 May 2020, 05:15
Kudos
Bookmarks
