【正确答案】 B

【答案解析】In each column, the sum includes the numbers from -3 to 3. Since all the other numbers in Column A are negative and those in Column B are positive, Column B is greater. (Note that we didn't have to calculate either sum. We just used TACTIC 5, Chapter 12 and com-pared the columns.)

【正确答案】 A

【答案解析】Since Y is inside the circle it is closer to the center than X, which is on the circle. Column A is greater.

【正确答案】 B

【答案解析】Since x + y = 1, at least one of the numbers is positive. If either x or y is 0, the product xy = 0; and if either one is negative, then xy is negative. In each case, xy is less than 1. If both x and y are positive, then each is less than 1, and so is their product. Column B is' greater.

【正确答案】 A

【答案解析】There is not enough information provided to determine the values of a, b, c, d, e, f, and g, but they are irrelevant. Since the sum of the measures of the seven angles is 360°, their average is 360° + 7 = 51.4°. Column A is greater.