MATH 350 Homework 01

  1. What is the samlpe space for the following random experiments?
    1. Zip codes are collected at a gas station.
    2. The lifetime of a computer on the Chico State campus.
    3. 50 random people are selected and the number of "morning-people" are counted.
  2. Suppose S={1,2,3,4,5,6}S = \{1, 2, 3, 4, 5, 6\}. Consider the sets A={1,2,3}A = \{ 1, 2, 3 \} and B={2,4,6}B = \{2, 4, 6 \}.
    1. Write in your own words the definition of the intersection of two sets.
    2. What set is the intersection of the sets AA and BB, ABA \cap B?
    3. Write in your own words the definition of the union of two sets.
    4. What set is the union of the sets AA and BB, ABA \cup B?
    5. Write in your own words the definition of the complement of the set AA, AcA^c.
    6. What set is the complement of AcA^c relative to SS?
    7. Provide a set that is a subset of SS, but different from AA and BB.
  3. Suppose S={A,E,I,O,U}S = \{ A, E, I, O, U \}. Provide three sets which form a partition of SS, e.g. are non-empty, mutually exclusive, and exhaustive of SS.
  4. Suppose A={a,b,c}A = \{ a, b, c \}. Provide a non-empty set which shares no items in common with AA, name it CC. What is the set defined by ACA \cap C? Identify the name of this set and write it out mathematically.
  5. What must be true of events AA and BB, if AB=BA \cup B = B, AB=AA \cap B = A, and ABA \neq B? Please write your answer using both symbols and words.
  6. Suppose A1,A2,,Ak A_1, A_2, \ldots, A_k are intervals of real numbers such that Ai={x:0x<1/i}A_i = \{x : 0 \leq x < 1 / i \} for i=1,2,,ki = 1, 2, \ldots, k. Using symbols and words, describe the sets
    1. i=1kAi\cup_{i=1}^k A_i
    2. i=1kAi\cap_{i=1}^k A_i