GWD 15

LeannaChina

Q21:
Martin has worked for the last 30 years.If his average (arithmetic mean) total annual earnings for the first 5 years is $15,000, what is his average total annual earnings for the last 5 years?
(1)Martin’s average total annual earnings for the first 25 years is $27,000.
(2)Martin’s average total annual earnings for the last 25 years is $34,000.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

恩。。答案是C  我认为只要B 就行啦 各位大侠帮忙看看哦 谢谢啦


In the figure shown, the circle has center O and radius 50, and point P has coordinates (50,0).If point Q (not shown) is on the circle, what is the length of line segment PQ ?
(1)The x-coordinate of point Q is – 30.
(2)The y-coordinate of point Q is – 40.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
Answer:
恩 答案是 A 如果 A对的话 B是不是也对呢 那是不是D呢。。。呵呵 谢谢啦


Q35:
For what percent of those tested for a certain infection was the test accurate; that is, positive for those who had the infection and negative for those who did not have the infection?
(1)Of those who tested positive for the infection,

1/8did not have the infection.(2)Of those tested for the infection, 90 percent tested negative.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案是E 恩 我认为是 C 因为 B 是90%是negative 然后 那 positive是不是就是10%呢 7/8是have infection 的呢 所以用10% *7/8 了呢。。。。各位大侠帮忙看看 谢谢啦 感激不尽啊 ！！！
In the figure shown, the circle has center O and radius 50, and point P has coordinates (50,0).If point Q (not shown) is on the circle, what is the length of line segment PQ ?
(1)The x-coordinate of point Q is – 30.
(2)The y-coordinate of point Q is – 40.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
Answer:
恩 答案是 A 如果 A对的话 B是不是也对呢 那是不是D呢。。。呵呵 谢谢啦


Q35:
For what percent of those tested for a certain infection was the test accurate; that is, positive for those who had the infection and negative for those who did not have the infection?
(1)Of those who tested positive for the infection,
1/8did not have the infection.(2)Of those tested for the infection, 90 percent tested negative.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案是E 恩 我认为是 C 因为 B 是90%是negative 然后 那 positive是不是就是10%呢 7/8是have infection 的呢 所以用10% *7/8 了呢。。。。各位大侠帮忙看看 谢谢啦 感激不尽啊 ！！！

LeannaChina

oh ~~~ I got it ~~thank you so much !!!

sdcar2010

No. The answer is A. If you only know the y coordinate, there are two possible points (same y, different x), thus insufficient. Draw a circle, draw the points, draw the two straight lines (same x or same y), and you will understand.

LeannaChina

therefore, as Q is on the circle,if you know 1 you can calculate where the point and then know the segment pQ , so  the answer is D ?

sdcar2010

in the piciture, the point P  is in the right side of the coordinate,on the X asis  and doesn't shown where Q is ...actually, I didn't quite understand the meaning of (1)The x-coordinate of point Q is – 30.  
is that mean that  if x is (a,b) and a =-30    ?

-- by 会员 LeannaChina (2011/2/22 8:14:57)

Yes.

LeannaChina

in the piciture, the point P  is in the right side of the coordinate,on the X asis  and doesn't shown where Q is ...actually, I didn't quite understand the meaning of (1)The x-coordinate of point Q is – 30.  
is that mean that  if x is (a,b) and a =-30    ?

sdcar2010

Q35:
For what percent of those tested for a certain infection was the test accurate; that is, positive for those who had the infection and negative for those who did not have the infection?
(1)Of those who tested positive for the infection,
1/8did not have the infection.(2)Of those tested for the infection, 90 percent tested negative.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案是E 恩 我认为是 C 因为 B 是90%是negative 然后 那 positive是不是就是10%呢 7/8是have infection 的呢 所以用10% *7/8 了呢。。。。各位大侠帮忙看看 谢谢啦 感激不尽啊 ！！！


The key here is that you do not know what percentage of the patients in the test are tested positive (or negative).  Without this info, you cannot calculate the accuracy defined in the stimulus. Use a paper and pencil approach, you will see.

sdcar2010

In the figure shown, the circle has center O and radius 50, and point P has coordinates (50,0).If point Q (not shown) is on the circle, what is the length of line segment PQ ?
(1)The x-coordinate of point Q is – 30.
(2)The y-coordinate of point Q is – 40.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
Answer:
恩 答案是 A 如果 A对的话 B是不是也对呢 那是不是D呢。。。呵呵 谢谢啦

Without the required picture I do not know the relative postion of P vs. O. If PO is horizontal on the X axis, condition 1 is sufficient, while condition 2 is not. Again, you need a paper and pencil approach to draw the lines and see for yourself.

sdcar2010

Q21:
Martin has worked for the last 30 years.If his average (arithmetic mean) total annual earnings for the first 5 years is $15,000, what is his average total annual earnings for the last 5 years?
(1)Martin’s average total annual earnings for the first 25 years is $27,000.
(2)Martin’s average total annual earnings for the last 25 years is $34,000.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

恩。。答案是C  我认为只要B 就行啦 各位大侠帮忙看看哦 谢谢啦

It is C.  Use a pencil and paper approach, and you will know.

Use the stimulus and condition 2, you can get the total for 30 years.  Then use condition 1), you can get the total for the LAST 5 years.