COUNTING METHODS REVIEW AND SELF TEST |
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Suggestions for this self exam:
[A] |
Study Rolf (sections 6.3, 6.4, 6.5), but then keep your book closed during this entire test |
[B] |
Method choice buttons (colored ovals) for each problem are scripted to show the correct choice
when the mouse arrow moves over them. Hence, keep your mouse restrained until you have thought
out your response.
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[C] |
Then type in your integer answer to the problem in the box provided,
rounding to the nearest dollar:
this page doesn't do arithmetic, so write "24" instead of "6 * 4" or "4!".
You may check each answer. |
[D] |
The 3 counting principles are reviewed in your text (Rolf): |
The MULTIPLICATION PRINCIPLE is in section 6.3 (Pg 455)
If Task A can be done in m ways, and Task B can be done in n ways,
then both tasks can be done in (mn) ways |
The PERMUTATIONS PRINCIPLE is in section 6.4 (Pg 468)
If k objects are selected from a larger collection of m objects, those k objects
can be lined up in a row in P(n,k) ways, where P(n,k) = n(n-1)(n-2)(n-3).......(n-k+1),
that is, the product of k integers starting downward from n |
The COMBINATIONS PRINCIPLE is in section 6.5 (Pg 479)
The number of subsets of size k which can be selected from a larger
set of size n is C(n,k) = [ P(n.k) divided by k! ] |
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[1] |
Two soups, 5 meat dishes, and 3 desserts are on the menu of
Neptune restaurant. How many different meals are possible,
each consisting of one soup, one meat dish, and one dessert?
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Choose method first ⇢ |
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[2] |
In how many ways can the letters of the word CREAM be arranged?
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[3] |
An ATM pin number consists of 4 digits, such as 1111, 0011 or
2345. How many such pin numbers are possible? |
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Choose method first ⇢ |
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[4] |
An ATM pin number consists of 4 DIFFERENT digits,
such as 1234, 8765, or 2345. In this version of the previous
problem, 0011 and 1111 are NOT allowed. How many such pin
numbers are now possible? |
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Choose best method first ⇢ |
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[5] |
A woman's wardrobe contains 2 blazers, 4 blouses, and 3 skirts.
Assuming any combination looks fine, how many "outfits" are
available in this wardrobe, each consisting of a blazer,
a skirt, and a blouse? |
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Choose best method first ⇢ |
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[6] |
Five finalists are to be chosen from 1O contestants in a contest.
How many such sets of 5 finalists are possible if the finalists are
ranked? |
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Choose best method first ⇢ |
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[7] |
In how many ways can the Supreme Court render a 5-4 decision
in support of the death penalty? |
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Choose best method first ⇢ |
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[8] |
Five people must line up in a row for a group photo. How many
different such group photos are possible? |
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Choose best method first ⇢ |
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[9] |
One way to answer a 1O-question true-false test is : T T T T T T T T T T.
Another way to answer this same test is : T T T T T T T T T F.
All together, how many ways are there to answer the questions
on this test? |
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Choose best method first ⇢ |
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[10] |
Five awards (1st, 2nd, 3rd, 4th, and 5th place) are to be
chosen for the five entrants in a pie contest. In how many
ways can these awards be assigned? |
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Choose best method first ⇢ |
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[11] |
How many 5-card poker hands are possible when dealing from
a 52-card deck? |
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[12] |
A 1O-member club must elect 4 officers: a president,
vice-president, secretary, and treasurer. How many different
election results are possible? |
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Choose best method first ⇢ |
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[13] |
A 5-person committee must be chosen from a 10-member club.
How many different such committees are possible? |
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Choose best method first ⇢ |
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[14] |
How many different arrangements are possible for 7 books on
a shelf? |
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Choose method first ⇢ |
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[15] |
In how many ways can each of 1O numbered billiard balls be
assigned to one of the 2 side pockets? Each pocket is big
enough to hold all 1O balls. |
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Choose best method first ⇢ |
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[16] |
Five non-permanent seats in the UN Security Council are to be
selected from among 10 countries. How many such sets of
5 nations are there? |
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Choose best method first ⇢ |
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