Consumer Math
Probability
Pointers
c. What is the probability
that you will win, written as a
fraction?
D. What is the probability that
you won’t win, written as a
fraction?
Example: What is the
probability (P) that the
spinner will land on blue?
1
_
P= 5 =
Tip: Zoom in for
easy reading!
3
A. It costs $3 to take a
guess. How much does
it cost to guess all the
possible outcomes and make
sure you win in one spin?
B. The prize is a stuffed
Scooby-Doo. You can buy one
at the store for $10. Is it worth
spending the money from 3a
to make sure you win?
favorable outcomes ( blue)
possible outcomes (any color)
supermath
1
_
You have a 5 (one in five)
chance that the wheel will
4
__
land on blue—and a 5 chance
that it won’t!
Use the wheel above to answer
questions 2 and 3.
2
Use probability to see what your chances are
of winning prizes at the carnival
W
IllustratIon by dave klug
elcome, ladies and gentlemen!
Step right up and try to win at
our wheel of fortune!
If you’ve been to a carnival, fair, or
amusement park, you’ve probably seen these
games. Players pay to guess which space the
spinner will stop on. Guess the correct space
and win a prize, such as a giant stuffed animal
or even a video game. Easy, right? Wrong.
The chances of winning a wheel game are
based on probability. Probability describes
how likely something is to happen. Carnivals
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Show your work here:
make money because they know that most
people won’t win a prize—or that the prize
isn’t worth as much as people pay to play!
Try our probability activity. You’ll see that,
when it comes to these games, your chances
of winning aren’t “wheely” good.
What to Do
Read Probability Pointers. Then answer
the questions about each wheel.
a. What is the
probability that the
spinner above will land on
the heart?
Use the wheel above to answer
question 1.
You pay $1 to guess that
the spinner above will
land on red.
A. What is the number of
favorable (winning) outcomes?
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b. What is the total number
of possible outcomes?
A. You play this game 36 times,
making one guess each time.
Based on probability, how many
times do you expect to win?
B. What is the probability that
it won’t land on the heart?
C. You pay to take two guesses
on one spin. You’ll win if the
spinner lands on either the
heart or the diamond. What is
the probability that you’ll win?
B. You pay $2 per spin to play
36 times, and you win the
number of times from A.
Each prize is worth $15. How
much more would you spend
playing the game than the
value of the prizes?
—By Carli Entin
May/June 2011
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