Answer B Discussed at level question 95183html 42

Answer b discussed at level question 95183html 42

This preview shows page 23 - 25 out of 31 pages.

Answer: B. Discussed at: 42. Coordinate Geometry If y is a negative number greater than -8, is x greater than the average (arithmetic mean) of y and -8 ? (1) On the number line, x is closer to -8 than it is to y. (2) x = 4y Given: . Q: is x greater than the average of -8 and x? Or: is ? --> ? ----- {-8} ----- {average} ----- {y} (average of y and -8 is halfway between y and -8). (1) On the number line, x is closer to -8 than it is to y. Now, as is closer to than it ( ) is to , then is either in the green area, so less than average OR in the red area, so also less than average. Answer to the question is NO. Sufficient. (2) --> is ? --> is ? --> is ? We don't now that. Not sufficient. (we've gotten that if (for instance if ), then the answer to the question is YES, but if (for instance if ), then the answer to the question is NO.) Answer: A. Discussed at: 43. Rate Problem
Image of page 23
Car X leaves Town A at 2 p.m. and drives toward Town B at a constant rate of m miles per hour. Fifteen minutes later, Car Y begins driving from Town B to Town A at a constant rate of n miles an hour. If both Car X and Car Y drive along the sameroute, will Car X be closer to Town A or Town B when it passes Car Y ? (1) Car X arrives in Town B 90 minutes after leaving city A.(2) Car Y arrives in Town A at the same time Car X arrived in Town B.(P meeting point). Question: is (1) Car X arrives in Town B 90 minutes after leaving city A. No info about car Y. Not sufficient.(2) Car Y arrives in Town A at the same time Car X arrived in Town B --> X needs 15 min longer than Y to cover the same distance (as Y starts 15 min after X) --> rate of X < rate of Y(m<n). Also, after they meet X and Y will need the same time to get to their respective destinations (as they arrived at the same time) --> the distance covered by Y after they meet (PA=nt) at higher speed, will obviously be more than the distance covered by X after they meet (PB=mt) at lower speed (or algebraically as m<n, mt<nt --> ). So . Sufficient.Answer: B.Discussed at: ? 44. Number PropertiesIs product 2*x*5*y an even integer?
Image of page 24
Image of page 25

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture