|
|
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.
16 Sep 2014, 00:44
Kudos
Bookmarks
Which of the following sets must have the same standard deviation as set \(\{a, \ b, \ c\}\)?
A. \(\{ab, \ b^2, \ cb\}\)
B. \(\{2a, \ b + a, \ c + b\}\)
C. \(\{0, \ b + a, \ c - a\}\)
D. \(\{ab, \ bc, \ ac\}\)
E. \(\{ab + c, \ a(1 + b), \ b(1+a)\}\)
A. \(\{ab, \ b^2, \ cb\}\)
B. \(\{2a, \ b + a, \ c + b\}\)
C. \(\{0, \ b + a, \ c - a\}\)
D. \(\{ab, \ bc, \ ac\}\)
E. \(\{ab + c, \ a(1 + b), \ b(1+a)\}\)
12 Jun 2020, 00:11
Kudos
Bookmarks
davidbeckham
Check the links below:
Backsolving on GMAT Math
How to Plug in Numbers on GMAT Math Questions
Why Approximate?
GMAT Math Strategies — Estimation, Rounding and other Shortcuts
The Power of Estimation for GMAT Quant
The 4 Math Strategies Everyone Must Master, Part 1 (1. Test Cases and 2. Choose Smart Numbers.)
The 4 Math Strategies Everyone Must Master, part 2 (3. Work Backwards and 4. Estimate)
Intelligent Guessing on GMAT
How to Avoid Tedious Calculations on the Quantitative Section of the GMAT
GMAT Tip of the Week: No Calculator? No Problem.
The Importance of Sorting Answer Choices on the GMAT
Identifying the Correct Answer on GMAT Quant Questions
How to Manage Unmanageable Numbers on the GMAT
Should You Double Check Your Answer Choices on the GMAT?
16 Sep 2014, 00:44
Kudos
Bookmarks
Official Solution:
Which of the following sets must have the same standard deviation as set \(\{a, \ b, \ c\}\)?
A. \(\{ab, \ b^2, \ cb\}\)
B. \(\{2a, \ b + a, \ c + b\}\)
C. \(\{0, \ b + a, \ c - a\}\)
D. \(\{ab, \ bc, \ ac\}\)
E. \(\{ab + c, \ a(1 + b), \ b(1+a)\}\)
If we add or subtract a constant to each term in a set, the standard deviation will not change.
Observe that set \(\{ab + c, \ a(1 + b), \ b(1+a)\}=\{c+ab, \ a+ab, \ b+ab\}\). This set is obtained by adding some number \(ab\) to each term of set \(\{a, \ b, \ c\}\). This means that these sets must have the same standard deviation.
Answer: E
Which of the following sets must have the same standard deviation as set \(\{a, \ b, \ c\}\)?
A. \(\{ab, \ b^2, \ cb\}\)
B. \(\{2a, \ b + a, \ c + b\}\)
C. \(\{0, \ b + a, \ c - a\}\)
D. \(\{ab, \ bc, \ ac\}\)
E. \(\{ab + c, \ a(1 + b), \ b(1+a)\}\)
If we add or subtract a constant to each term in a set, the standard deviation will not change.
Observe that set \(\{ab + c, \ a(1 + b), \ b(1+a)\}=\{c+ab, \ a+ab, \ b+ab\}\). This set is obtained by adding some number \(ab\) to each term of set \(\{a, \ b, \ c\}\). This means that these sets must have the same standard deviation.
Answer: E
