If s is an integer between 0 and 10, is t less than the average (arithmetic mean) of s and 10?
(1) t is closer to 10 on the number line than it is to s.
(2) t is 5 times as large as s.
If s is an integer between 0 and 10, is t less than the av
This topic has expert replies
- GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
The average of s and 10 lies HALFWAY between s and 10 on the number line:subh2273 wrote:If s is an integer between 0 and 10, is t less than the average (arithmetic mean) of s and 10?
(1) t is closer to 10 on the number line than it is to s.
(2) t is 5 times as large as s.
s------------AVERAGE------------10
Statement 1:
Since t closer to 10 than to s, t must be greater than the average of s and 10, as shown here:
s-----------AVERAGE---t----------10
Thus, the answer to the question stem is NO.
Statement 2:
Case 1: s=1 and t = 5*1 = 5, with the result that the average of s and 10 = (1+10)/2 = 5.5.
In this case, t is less than the average of s and 10, so the answer to the question stem is YES.
Case 2: s=2 and t = 5*2 = 10, with the result that the average of s and 10 = (2+10)/2 = 6.
In this case, t is greater than the average of s and 10, so the answer to the question stem is NO.
INSUFFICIENT.
The correct answer is A.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
- fskilnik@GMATH
- GMAT Instructor
- Posts: 1449
- Joined: Sat Oct 09, 2010 2:16 pm
- Thanked: 59 times
- Followed by:33 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
\[1 \leqslant s \leqslant 9\,\,\,\,\operatorname{int} \,\,\,\left( * \right)\]subh2273 wrote:If s is an integer between 0 and 10, is t less than the average (arithmetic mean) of s and 10?
(1) t is closer to 10 on the number line than it is to s.
(2) t is 5 times as large as s.
\[t\,\,\mathop < \limits^? \,\,\frac{{s + 10}}{2}\]
\[\left( 1 \right)\,\, \Rightarrow \,\,\,\,\left\{ \begin{gathered}
\,\,t \geqslant 10\,\,\,\,\mathop \Rightarrow \limits^{{\text{FOCUS}}!} \,\,\,t \geqslant \frac{{10 + 10}}{2}\,\,\,\mathop > \limits^{\left( * \right)} \,\,\,\frac{{s + 10}}{2}\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\left\langle {{\text{NO}}} \right\rangle \,\,\,\,\,\, \hfill \\
\,\,{\text{OR}} \hfill \\
\,s < \,\,\boxed{\,\,\frac{{s + 10}}{2} < t\,\,}\,\, < \,\,\,10\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\left\langle {{\text{NO}}} \right\rangle \hfill \\
\end{gathered} \right.\]
\[\left( 2 \right)\,\,\,\left\{ \begin{gathered}
\,{\text{Take}}\,\,s = 1\,\,\,\, \Rightarrow \,\,\,\,t = 5\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\left\langle {{\text{YES}}} \right\rangle \,\, \hfill \\
\,{\text{Take}}\,\,s = 2\,\,\,\, \Rightarrow \,\,\,\,t = 10\,\,\,\,\, \Rightarrow \,\,\,\,\left\langle {{\text{NO}}} \right\rangle \hfill \\
\end{gathered} \right.\]
This solution follows the notations and rationale taught in the GMATH method.
Regards,
Fabio.
Fabio Skilnik :: GMATH method creator ( Math for the GMAT)
English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br
English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br