Question: In how many ways can change
amounting to a given amount be made?
1.
Using pennies,
nickels, dimes and quarters, make a list of all the ways to make $0.12. Repeat
for $0.27, $0.43.
Each of the possible ways of using coins to
make a given amount of change is called a coin changing. These are special
cases of what are known as numerical partitions of any positive integer. A
numerical partition of an integer n is a sequence of integers called parts
whose sum is n. For example, a partition of 14 is 6+4+2+1+1.
Note that the parts are listed from largest
to smallest.
2.
Find all the
numerical partitions of the numbers 1 through 7.
The number of partitions of a given number n
is denoted by p(n).
3.
Make a table of
your results in #2 with columns listing n and p(n).
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n |
p(n) |
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1 |
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2 |
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3 |
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Every numerical partition of a number n
corresponds to a unique "Ferrer's diagram".
This is formed by an arrangement of n dots on a grid where each part in
the partition is represented by placing the same number of dots in a row. Below
is the Ferrer's diagram for the partition 7+4+4+1+1+1
of n = 18.
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7 |
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4 |
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4 |
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1 |
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1 |
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1 |
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4.
Draw the Ferrer's diagrams for the partitions of 5. Repeat for the
partitions of 6.
Note: Two Ferrer's
diagrams are conjugate pairs if one diagram can be transformed into the
other by changing rows into columns and columns into rows. A Ferrer's diagram is self-conjugate if changing rows
and columns leaves the diagram unchanged.
5.
Use your Ferrer’s diagrams to find all the conjugate pairs and
self-conjugate partitions of 5. Repeat
for 6.