Question 3
A digital scale is used that provides weights to the nearest gram.
a)
What is the sample space for this experiment?
Answer: Integers from 0 to infinity (since no upper weight limit was given for the scale)
Let A denote the event that a weight exceeds 11 grams, let B denote the event that a
weight is less than or equal to 15 grams, and let C denote the event that a weight is
greater than or equal to 8 grams and less than 12 grams.
Describe the following events.
b)
A
∪
B
c)A
∩
B
d)A
′
e) A
∪
B
∪
C
f) (A
∪
C)
′
g) A
∩
B
∩
C
h) B
′∩
C
i) A
∪
B
∩
C
a) Answer: S= nonnegative integers from 0 to the largest integer that can be displayed
by the scale S={0,1,2,3,…}
b)
S
c) {12, 13, 14, 15}
d) {0,1, 2,…,11}
e)
S
f){0,1,2,….7}
g) Ǿ
h)Ǿ
i) {8,9,10,…}
Question 4
An experiment consists of flipping a coin and then tossing a die once if the coin shows
head. If the coin shows tail, the die is tossed twice.
a)
Describe the sample space by listing its elements.
b)
Describe the sample space using a tree diagram.
Answer:
a)
S= {(H1), (H2), (H3), (H4), (H5), (H6), (T11), (T12), (T13), (T14), (T15), (T16),
(T21), (T22), (T23), (T24), (T25), (T26), (T31), (T32), (T33), (T34),
(T35), (T36), (T41), (T42), (T43), (T44), (T45), (T46), (T51) , (T52),
(T53), (T54), (T55), (T56), (T61), (T62), (T63), (T64), (T65), (T66)}
b)