下面这3道题感觉之前都见过，但看了prep和做过的几套GWD，也搜了CD的帖子，都没找到，只好发帖求助：
MATH 21
Q22:In triangle ABC, point X isthe midpoint of side AC and point Y is the midpoint of side BC. If point R is the midpoint of linesegment XC and if point S is the midpoint of line segment YC,what is the area of triangular region RCS ? (1) Thearea of triangular region ABX is 32. (2) Thelength of one of the altitudes of triangle ABC is 8. A. Statement (1) ALONE issufficient, but statement (2) alone is not sufficient. B. Statement (2) ALONE issufficient, but statement (1) alone is not sufficient. C. BOTH statements TOGETHERare sufficient, but NEITHER statement ALONE is sufficient. D. EACH statement ALONE issufficient.
E. Statements (1) and (2) TOGETHERare NOT sufficient.
答案是A，不知怎么算出来的。
Q23: On a certain transatlantic crossing, 20percent of a ship’s passengers held round-trip tickets and also took their carsabroad the ship. If 60 percent of thepassengers with round-trip tickets did not take their cars abroad theship, what percent of the ship’s passengers held round-trip tickets? A. (33+1/3)% B. 40% C. 50% D. 60% E. ( 66+2/3)% 答案是C，可我算出来是60%也就是D
Q25: If M isthe least common multiple of 90, 196, and 300, which of the following is NOT afactor of M ? A. 600 B. 700 C. 900 D. 2,100 E. 4,900 答案是A，可是怎么算出来的呢？
GWD 22 Q29
In the xy-plane, region Rconsists of all the points (x, y) such that 2x + 3y≤ 6. Is the point (r, s)in region R ? (1) 3r+ 2s = 6 (2) r≤ 3 and s ≤ 2 A. Statement (1) ALONE issufficient, but statement (2) alone is not sufficient. B. Statement (2) ALONE issufficient, but statement (1) alone is not sufficient. C. BOTH statements TOGETHERare sufficient, but NEITHER statement ALONE is sufficient. D. EACH statement ALONE issufficient. E.Statements (1) and (2) TOGETHER are NOT sufficient.
答案是E，凭感觉能猜出来，但不知如何解题，请牛人指点。
以上4道题，还请过路的牛人帮忙解答~~多谢~~！
| 
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2014-10-25 21:15:46
收藏
收藏
楼主
up up~
不客气