Math 12 Foundations
Probability Unit
Introduction to Probability
PROBABILITY -
FORMULA _
Ex.
A bag of marbles contains 12 blue, 1O red, and 8
at random ...
A) find the probability that it is blue.
white. If one is chosen
B) find the probability tJ:at it is not red.
C) find the probability that it is red or white.
Ex.
One card is dealt from a well-shuffled deck of cards. What is the
probability that the card is ...
A) a nine?
B) a heart?
C) not a face card?
D) a black ace?
Math 12 Foundations
Probability Unit
Practice Problems
1. A bag ofjellybeans contains 12 orange,
chosen at random ...
A) find the probability that it is yellow.
1O
yellow, and 8 black. If one is
B) Iind the probability that it is not orange.
C) find the probability that it is orange or black.
2. A box of Smarties contains 12 red, 10 green, 11 purple, and 7 yellow. If
one is chosen at random ...
A) find the probability that it is green.
B) find the probability that it is purple or yellow.
C) find the probability that it is not red.
D) find the probability that it is not red or purple.
3. One card is dealt from
cards. (assume a standard
deck af 52 cards) What is the probability that the card is ...
E) a red 1O?
A) an ace?
a well-shuffled deck of
B) a club?
F) not a black face card?
C) red?
G) not a diamond?
D) a face card?
H) not a queen?
Math 12 Foundations
Probability Unit
Worksheet I
Wri!9 whelhel eac! evelt is lertaln,lilely,
1.
u!!!ely,
at
A number from the following list is chosen
random: 73,13,57,29,71,and 9. Describe the
probability of picking an odd number.
or lnpos-sible,
2 The following coins are put in a bag:
Describe the probability of picking a penny.
A glass jar contains a total of 33 marbles. The jar has
A number from the following list is chosen at
random: 99, 2, 83, 26, 66, 10, 97,12,14, andl.
Describe the probability of picking an odd number.
red and blue marbles. There are 7 blue marbles.
Describe the probability of picking a red marble.
Write th9 pp-bati!'ty1
5.
A bag contains 4 yellow marbles, 9 green marbles, 4
blue marbles, 4 red marbles, and 15 purple marbles.
What is the probability of pulling out a green marble?
lf one letter is chosen at random from the word
crocheted, what is the probability that the letter
chosen is the letter "c"?
I outof_
7.
_
lf one letter is chosen at random from the word
individuality, what is the probability that the letter
chosen is the letter'n'?
_
ouJ of
out of-_9_
lf one letter is chosen at random from the word
drugging, what is the probability that the letter chosen
is the letter "i'?
1
_ll
outof
Write the probability.
L
lf one letter is chosen at random from the word
therefore, what is the probability that the letter chosen
is the letter "r"?
10.
A number cube has 6 sides. The sides are
numbered 1 to 6. lf the cube is thrown once, what is
the probability of rolling the number 1 or the number
6?
_outof_
1 1
.
A number cube has 6 sides. The sides have the
numbers 5, 6, 7, 9, 9, and 3. lf the cube is thrown
once, what is the probability of rolling the number 9?
_outof_
_
out
of_
12. A bag contains 5 blue marbles, 5 yellow marbles, 3
purple marbles, 6 green marbles, and 11 red
marbles. What is the probability of pulling out a blue
or a red marble?
_
out
of_
l2 Foundations
Probability Unit
Worksheet 2
Math
5ffi 6ffi
The letter C.
,l o't'f ,,
2
The letter D.
outof
The letter D.
5
4
,
-outof
ltlrite whether each event is cerhin, likely, unlikely, or mpossible,
18.
The following coins are put in a
-outof
The following coins are put in a bag:
Describe the probability of picking a penny.
Describe the probability of picking a penny.
Wrile
19.
ffi
\E"l-sl
The letter A.
_
Writglhe-
23.
out
of_
20.
\l-:/E.
The letter
_
out
of_
21
ffi
ffi
\E.1-El
The letter E
_
out
of_
The letter F.
_
out
of_
prob{i!ity.
lf one letter is chosen at random from the word
represented, what is the probability that the letter
chosen is the letter "r'?
out
25.
,ffi\
Flflq
t!e probability of 9-qinning each letter.
24. A bag contains 10 green marbles, 12 blue marbles,
19 purple marbles, 3 yellow marbles, and 13 red
marbles. What is the probability of pulling out a
green or a blue marble?
of-
A number cube has 6 sides. The sides are
numbered 1 to 6. lf the cube is thrown once, what is
the probability of rolling the number 2?
_outof^
26. A number cube has 6 sides. The sides are
numbered 1 to 6. lf the cube is thrown once, what is
the probability of rolling the number 2 or the number
3?
-outof-
_
out
of_
Math 12 Foundations
Probability Unit
Worksheet 3
Find the probability. Yllrite your answer as a percent rounded to the nearest whole percent.
1.
You rolla numbercube numbered from 1 to
6.
2.
A numberfrom 10 to 19 is drawn at random.
P(a number greater than 19) =
4.
A jar contains 1 5 navy and 1 6 orange marbles. A
P('t)=
3.
A jar contains
1
1 navy, 16 yellow, and 1 6 green
marbles. A marble is drawn at random.
P(navy or green) =
A jar contains 5 navy and 4 red marbles. A
marble is drawn at random.
marble is drawn at random.
P(not navY) =
6.
You roll a number cube numbered from 1 to 6.
P(4, 6, 3, or 2) =
P(red)=
7.
You roll a number cube numbered from 1 to 6.
8.
P(not a 3) =
You roll a number cube numbered from 1 to 6.
10.
P(4 or 2) =
11. A numberfrom 18 to 30 is drawn at random.
A numberfrom 20 to 30 is drawn at random.
P(a composite number) =
A numberfrom 15 to 27 is drawn at random.
P(a number divisible by 2) =
12. You roll a number cube numbered from 1 to 6.
P(5)=
P(not a 20) =
13.
You roll a number cube numbered from 1 to 6.
P(an odd number)=
14. A jarcontains 21 pink,20 white, 19 yellow, and
6 navy marbles. A marble is drawn at random.
P(white, navy, or pink) =
15.
A jar contains 9 green and 11 navy marbles. A
16.
marble is drawn at random.
P(not green) =
17. You roll a number cube numbered from 1 to 6.
P(a number less than 6) =
A jar contains 19 violet, 17 yellow, 20 gray, and
5 blue marbles. A marble is dnawn at random.
P(blue)=
18.
You roll a number cube numbered from 1 to 6.
P(an even number) =
Math 12 Foundations
Probability Unit
Worksheet 4
Find the probability. Write your answer as a fraction in simplest form.
1
,
A jar contains 19 black, 22 pink,21 purple, and
violet marbles. A marble is drawn at random.
1
1
2. A number from 23 to 35 is drawn at random.
P(an even number).
P(black).
3.
A jar contains 17 nauy and 20 green marbles. A
marble is drawn at random.
4.
A number from 10 to 17 is drawn at random.
P(a number divisible by 3).
P(not navy).
5.
A jar contains 19 blue, 21 violet, and 15 orange
marbles. A marble is drawn at random.
You roll a number cube numbered from 1 to 6,
P(not a 6).
P(orange or blue).
7.
You roll a number cube numbered from 1 to 6.
P(a composite number).
You roll a number cube numbered from 1 to 6.
P(2).
You roll a number cube numbered tom 1 to 6.
10.
P(5 or 1).
11. A jar contains 20 brown, 23 red, 13 orange, and 4
pink marbles. A marble is drawn at random.
P(pink).
13.
A jar contains 7 orange and 15 white marbles.
marble is drawn at random.
A
You roll a number cube numbered from 1 to 6.
P(a number less than 3).
12. A jar contains 6 black, 17 blue, 11 yellow, and 20
green marbles. A marble is drawn at random.
P(not green).
14. A number from 20lo 29 is drawn at random.
P(a composite number).
P(white).
You roll a number cube numbered from 'l to 6.
P(an even number).
16.
A number from 23 to 33 is drawn at random.
P(a number divisible by 3).
17. You roll a number cube numbered from 1 to 6.
18.
You roll a number cube numbered from 1 to 6.
15.
P(5)
P(3,6, or4).