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stucco005

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  1. 2. First Distance = Second Distance Time1*Speed1 = Time2*Speed2 4*Speed1 = 2*Speed2 2*Speed1 = Speed2 Pick Speed1 = 26 (in range). Thus, Speed2 = 52 (also in range). So, Distance1 = 26*4 = 104. Hmmm, this fits the description, but it is not among the answer choices, so must increase the speed. Try Speed1 = 29, So Speed2 = 58 Now, 4*29 = 116. Ans A. Note, that it cannot be B because that would require Speed2 = 60mph, and the range is BETWEEN (not inclusive) 45 and 60.
  2. The key is that these integers are "consecutive". From that simply do a weighted average to figure out what the average (and median in this case) is. From that, you'll be able to determine what the entire list of numbers is.
  3. A is the correct answer. Simply because if the BF portion is not the conclusion, then what is?
  4. The correct answer is B. If it is true that the predictions could be made by other means, it would show that perhaps the predictor is not that special in predicting her fortunes, that in fact she gets it from somewhere else.
  5. What if I asked you to find the average weight of 7 poeple, 5 of whom weigh an average of 175 lbs and the other 2 whom weigh an average of 300 lbs? How would you set up and solve that equation? Here's how: [5(175) + 2(300)]/7 = 1475/7 ~ 210 Now apply that same concept here: Let D = the number of directors. Likewise, let M = number of managers Let A = the average of salary of both D and M So, Using (1) and (2) together (and remembering the above example) we get: [(15000 + A)D + (A - 5000)M]/(D + M) = A 15000D + DA + MA - 5000M = DA + MA 15000D = 5000M 3D = M. So, remeber our original desire was to solve D/(D + M)? Then just substitue M for 3D and get D/(D + 3D) = D/4D = 1/4. Ans C.
  6. Please provide a detailed explination. Thanks! Ok, Since no one is answering my question I will attempt to do so by looking at the information given in the stem. Since the battery lives are symmetric about the mean, then that means that all values are equi distance from one another. For example, lets say 50 is the mean and 2 is the distance, then we could have: ....46 48 50 52 54... Now looking at the how the numbers relate (and knowing the answer!) it appears that for standard deviations which involve equi distances from the mean that one devaition below and one deviation above divides symettrially the distribution above and below. Thus, you can get the answer by using both (1) and (2) (1) tells you that 68 percent of the distribution is one deviation above and below the mean. That means 32 percent of the distribution remains for the top and the bottom, thus 32/2 = 16 percent exists in both top and bottom halfs. (2) tells you that 16% exists in the bottom half. Since we are dealing with the symetric properites of the equation this means the top half is also 16%. Anybody want to 2nd/challege that?
  7. If you take a = 2, and b = 3. The coordinates are (-2, 3) and (-3, 2), which are in the same quadrant. Notice that the negative sign always stays with the X coordinate.
  8. In data suff questions, work out an equation or target the answer before diving into the additional data. 1. Let M = manager, D = director Needed: D/(D + M) (1) INSUFF, no information about D. (2) INSUFF, no information about M. (1) and (2): Setup and equation for the averages: 15000D + (-5000M)/[M+D] = 0 Note: use 0 as the average since the data specifies above and below. Solve to get: 1D to 3M, thus the percent of directors to managers is (1 director)/(4 total) 2. This is a Venn Diagram question, and is best solved by drawing such a diagram and filling in the values. An equation for this type of problem is: Total = All_Group1 + All_Group2 - Both + Neither. In this problem, the stem tells us that "each of the 128 people attended" so we can throw out the "Neither" portion of the formula above, and are left with: 128 = Morning_People + AfterNoon_People - Both. Now, the trick is to recognize that both the Morning_People value and the AfterNoon_People value contain the Both value. (That is why you must subtract the Both value so you can eliminate that value when the two Group values overlap). (1) INSUFF: Only tells you the Both parameter in the question. (2). SUFF: This tells you that: AfterNoon_People_ONLY + Both = (7/8), thus (1/8) = Morning_People_ONLY. So the answer is (1/8)128
  9. That value pair was only intended as an extreme value for (1) in order to create a YES case for m > 3z. When (1) and (2) are combined you will have readjust your extremes.
  10. Hey guys, I agree with the OA. If m is some integer and m/3 has two different prime factors then that simply means that m has 3 prime factors. Namely, 3 and the other two prime factors mentioned in (2). Thus, answer B is sufficient.
  11. (thousands)(hundreds)(tens)(units).(tenths)(hundredths)(thousandths)
  12. I do not go by any rigid rules, but I do use extremes. By extremes I mean values that can cause the inequalities to change. A checklist could be 0, values between -1 and 1 (decimal values) -ve and +ve values. (Generally large numbers in either direction) Generally you can tell from the problem what values would be approriate. For an example, I'll answer your second question above: Simplify: m > -z ? (1) Simplify: m > 3z Go through checklist: Assume: m=100,z=1 (YES), m=0; z=-1 (NO) INSUFF. (2) Simplify: 4z > m Go through checklist: Assume: m=2, z=1 (YES); m=-5, z=-1 (NO) INSUFF. NOW, add both equations to get z > 0 Since z > 0, go back through all the value pair sets above and strike out the value pairs that have z -z remain. Ans C.
  13. For plugging in with inequalities, First I simply the equation asked for and then I use small values that make for easy computations and comparisons. 1. (1) says that X - Y = 1/2. This is insuff. Consider X = 1, Y = 1/2 AND X = 0, and Y = -1/2 (2) tells you that the sign of X and Y are equal AND also that X's absolute value is greater than that of Y's. Together, we find that X must be greater/equal to 1 since it is the only way to yeild a positive value given that X's absolute value is greater than Y.
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