155 multiple-choice questions on Sets and Functions from Mathematics, each with the correct answer and, where available, a teacher's explanation. Read through them to revise the chapter, then practise the same questions one by one to test yourself.
51. The relation “is less than” on A = 1, 2, 3 is:
(1, 2), (2, 3)
(1, 2), (1, 3), (2, 3)
(2, 1), (3, 1), (3, 2)
(1, 1), (2, 2), (3, 3)
Answer: B) (1, 2), (1, 3), (2, 3)
Explanation: List every pair (a, b) with a < b: (1, 2), (1, 3), (2, 3). SLO M-09-A-16 · Application
57. Out of 34 patients, 12 have fever, 19 have a cough and 5 have both. How many patients are in exactly one of the two groups?
26
8
7
21
Answer: D) 21
Explanation: At least one = 12 + 19 - 5 = 26; first group only = 7; second group only = 14; exactly one = 21; neither = 34 - 26 = 8. So the answer is 21. SLO M-09-A-14 · Application
65. In a survey of 100 families: 50 read Jang, 40 read Dawn, 30 read Express; 15 read Jang and Dawn, 10 read Dawn and Express, 12 read Jang and Express, and 5 read all three. How many read none of them?
88
12
13
17
Answer: B) 12
Explanation: At least one = 50 + 40 + 30 - 15 - 10 - 12 + 5 = 88, so none = 100 - 88 = 12. SLO M-09-A-14 · Application
69. Out of 43 patients, 22 have fever, 27 have a cough and 10 have both. How many patients have neither symptom?
12
4
29
39
Answer: B) 4
Explanation: At least one = 22 + 27 - 10 = 39; first group only = 12; second group only = 17; exactly one = 29; neither = 43 - 39 = 4. So the answer is 4. SLO M-09-A-14 · Application
70. In a town survey of 46 people, 21 speak Urdu at home, 23 speak Punjabi at home and 11 speak both. How many people speak Urdu only (not Punjabi)?
33
10
13
22
Answer: B) 10
Explanation: At least one = 21 + 23 - 11 = 33; first group only = 10; second group only = 12; exactly one = 22; neither = 46 - 33 = 13. So the answer is 10. SLO M-09-A-14 · Application
71. Verify the distributive law of union over intersection: with A = 1, 2, 5, 6, 7, B = 1, 5, 7, 10, C = 2, 3, 5, 7, both A cup (B cap C) and (A cup B) cap (A cup C) equal:
1, 2, 3, 5, 6, 7, 10
2, 5, 7
1, 2, 5, 6, 7
5, 7
Answer: C) 1, 2, 5, 6, 7
Explanation: Working out each side separately gives the same set 1, 2, 5, 6, 7, which verifies A cup (B cap C) = (A cup B) cap (A cup C). SLO M-09-A-13 · Application