经企管理研究生入学考试GMAT-Data-Sufficiency-Questions-With-Explanations.doc

700+ GMAT Data Sufficiency Questions With Explanations Collected by Bunuel Solutions by Bunuel 1. ?Probability / Combinatorics If 2 different representatives are to be selected at random from a group of 10 employeesand if p is the probability that both representatives selected will be women, is p 1/2(1) More than 1/2 of the 10 employees are women.(2) The probability that both representatives selected will be men is less than 1/10What is the probability of choosing 2 women out of 10 people??and this should be?. So we have??--??this is true only when?. (w # of women?)So basically question asks is??(1)??not sufficient.(2)??--??--?, not sufficient(1)+(2)?,??not sufficientAnswer E.You can use Combinations, to solve as well:?# of selections of 2 women out of??employees;?total # of selections of 2 representatives out of 10 employees.Q is??--??-- --??--??(1)?, not sufficient.(2)??# of selections of 2 men out of??employees --??--??--??--?, not sufficient(1)+(2)?,??not sufficientAnswer E. Discussed at: /forum/difficulty-faced-during-test-89934.html 2. Coordinate Geometry If vertices of a triangle have coordinates (-1,0), (4,0), and (0,A) , is the area of the triangle greater than 15?(1) A 3(2) The triangle is right First of all right triangle with hypotenuse 5,?doesnt mean?that we have (3, 4, 5) right triangle. If we are told that values of all sides are integers, then yes: the only integer solution for right triangle with hypotenuse 5 would be (3, 4, 5).To check this: consider the right triangle with hypotenuse 5 inscribed in circle. We know that a right triangle inscribed in a circle must have its hypotenuse as the diameter of the circle. The reverse is also true: if the diameter of the circle is also the triangle’s hypotenuse, then that triangle is a right triangle.So ANY point on circumference of a circle with diameter??would make the right triangle with diameter. Not necessarily sides to be??and?. For example we can have isoscel