7th Grade Math

(Marvins-Underground-K-12) #1
446 Probability and Predictions

= Step-by-Step Solutions begin on page R1.
Extra Practice begins on page EP2.

Example 1^55 CONTESTS In the Battle of the Bands contest, in how many ways can the
four participating bands be ordered?


  1. CODES A garage door code has 5 digits. If no digit is repeated, how many
    codes are possible?

  2. LETTERS How many permutations are possible of the letters in the word
    friend?

  3. NUMBERS How many different 3-digit numbers can be formed using the
    digits 9, 3, 4, 7, and 6? Assume no number can be used more than once.


Example 2 9. CAPTAINS The members of the Evergreen Junior Evergreen Junior High
Quiz Bowl Team
Jamil Luanda
Savannah Mi-Ling
Tucker Booker
Ferdinand Nina
Walter Meghan

High Quiz Bowl team are listed in the table.
If a captain and an assistant captain are chosen
at random, what is the probability that Walter
is selected as captain and Mi-Ling as co-captain?


  1. BASEBALL Adriano, Julián, and three of their
    friends will sit in a row of five seats at a baseball
    game. If each friend is equally likely to sit in any
    seat, what is the probability that Adriano will sit
    in the first seat and Julián will sit in the second seat?

  2. GAMES Alex, Aiden, Dexter, and Dion are playing a video game. If they
    each have an equally likely chance of getting the highest score, what is
    the probability that Dion will get the highest score and Alex the second
    highest?

  3. BLOCKS A child has wooden blocks with the letters shown below. Find
    the probability that the child randomly arranges the letters in the order
    TIGER.


B 1313 PHOTOGRAPHY The Coughlin family discovered they can stand in a row
for their family portrait in 720 different ways. How many members are in
the Coughlin family?


  1. SCHOOL Hamilton Middle School assigns a four-digit identification
    number to each student. The number is made from the digits 1, 2, 3, and
    4, and no digit is repeated. If assigned randomly, what is the probability
    that an ID number will end with a 3?


440_447_C08_L1_895130.indd 446 12/29/09 1:18 PM

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