21

5. B

6. H

9. {1, 2, 3, 4, 5, 6}

10. {9, 10, 11, 12, 13, 14, 16, 17}

12. {5, 6, 7, 8, 9, 10, 11, 12, 13}

15. {-15, -13, -11, -9, -7, -3, -1}

18. {90, 87, 84, 81, 78, 75, 72, 69}

21. {21, 22, 23, 24, 25?

24. {Richard M. Nixon, Gerald R. Ford, James ?immy?Carter}

25. {5, 10, 15, 20, 25?

27. {1, ? 1/3, ? 1/5?

30. {2x|x is in N}

33. Finite

35. Infinite

36. Infinite

39. Infinite

40. Finite

42. 7

45. 26

48. 100

50. 18

51. Infinite

55. Well defined

57. Not well defined

60. ∈

63. ∈

66. ∈

69. False

70. False

72. True

75. True

78. True

80. True

81. True

84. True

85. False

87. True

93. {a, b} & {a. c}

95. a) {LU, NT, PFE, GE}

b) {GE, MOT, TWX, C, TXN, EMC, AWE}

This worked, but this isn't the SEND file from the Query program.

You should be running the q_a_ program at the beginning of each assignment, and the Query program at the end.

Any problem submitted must contain an explanation of all the reasoning necessary to solve it.

It is not practical to submit a document containing this information for all problems. The Query is intended for this purpose. After you finish working out the problems, you run the Query, which in addition to your responses write a lot of information into SEND the file to save you a lot of work.