Last visit was: 23 Jul 2024, 08:03 It is currently 23 Jul 2024, 08:03
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.
Close
Request Expert Reply
Confirm Cancel
SORT BY:
Kudos
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 10133
Own Kudos [?]: 17048 [1]
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
Send PM
Retired Moderator
Joined: 22 Aug 2013
Posts: 1181
Own Kudos [?]: 2555 [0]
Given Kudos: 459
Location: India
Send PM
GMAT Club Legend
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6804
Own Kudos [?]: 30852 [0]
Given Kudos: 799
Location: Canada
Send PM
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 10133
Own Kudos [?]: 17048 [0]
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
Send PM
Re: Four values from a data set of 5 elements are 10, 10, 11, and 11. What [#permalink]
Expert Reply
=>

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

Since we have 1 variable, x which is the fifth data value and 0 equations, D is most likely to be the answer. So, we should consider each of the conditions on their own first.

Condition 1):
The fifth data value could be \(x = 9\) or \(x = 12\).
Since we don’t have a unique solution, condition 1) is not sufficient.

Condition 2):
\(\frac{( x + 10 + 10 + 11 + 11 )}{5} > 10\)
\(=> x + 10 + 10 + 11 + 11 > 50\)
\(=> x + 42 > 50\)
\(=> x > 8\)
Since we don’t have a unique solution, condition 2) is not sufficient.

Conditions 1) & 2) :
Condition 1) tells us that \(x = 9\) or \(x = 12\), and condition 2) tells us that \(x > 8\).
So, \(x = 9\) or \(x = 12\).
Since we don’t have a unique solution, both conditions together are not sufficient.

Therefore, E is the answer.

Answer: E

If the original condition includes “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations” etc., one more equation is required to answer the question. If each of conditions 1) and 2) provide an additional equation, there is a 59% chance that D is the answer, a 38% chance that A or B is the answer, and a 3% chance that the answer is C or E. Thus, answer D (conditions 1) and 2), when applied separately, are sufficient to answer the question) is most likely, but there may be cases where the answer is A,B,C or E.
Manager
Manager
Joined: 11 Feb 2013
Posts: 201
Own Kudos [?]: 305 [0]
Given Kudos: 60
Location: United States (TX)
Concentration: Finance
GMAT 1: 490 Q44 V15
GMAT 2: 690 Q47 V38
GRE 1: Q165 V155
GPA: 3.05
WE:Analyst (Commercial Banking)
Send PM
Re: Four values from a data set of 5 elements are 10, 10, 11, and 11. What [#permalink]
Statement 1:
If the fifth number is 9, range = 11-9=2.
If the fifth number is 12 range = 12-10=2.
So, fifth number can be 9 or 12.
INSUFFICIENT.

Posted from my mobile device
Manager
Manager
Joined: 11 Feb 2013
Posts: 201
Own Kudos [?]: 305 [0]
Given Kudos: 60
Location: United States (TX)
Concentration: Finance
GMAT 1: 490 Q44 V15
GMAT 2: 690 Q47 V38
GRE 1: Q165 V155
GPA: 3.05
WE:Analyst (Commercial Banking)
Send PM
Re: Four values from a data set of 5 elements are 10, 10, 11, and 11. What [#permalink]
Statement 2:
Average of five numbers is GREATER than 10. That means, TOTAL of the five numbers is greater than 50.
Sum of know four numbers is 42.
So, the fifth number will be GREATER than 8. That is, the fifth number can be anything such as 9,10,11,12, etc.
INSUFFICIENT.

Combining both statements,
9 &12 Are common in both statements (9&12 suffice both statements).
So, the fifth number can be 9 or 12.
INSUFFICIENT.

E answer

Posted from my mobile device
GMAT Club Bot
Re: Four values from a data set of 5 elements are 10, 10, 11, and 11. What [#permalink]
Moderator:
Math Expert
94586 posts