Finite State Machine
Mathematics · FE Reference Handbook section
Handbook notes for this section
Definitions and conditions exactly as the handbook states them.
- A finite state machine consists of a finite set of states
- A state (or truth) table can be used to represent the finite state machine.
- Another way to represent a finite state machine is to use a state diagram, which is a directed graph with labeled edges.
- The characteristic of how a function maps one set (X) to another set (Y) may be described in terms of being either injective,
- An injective (one-to-one) relationship exists if, and only if,
- A bijective relationship is both injective (one-to-one) and surjective (onto).
Core formulas for this FE topic
Definitions, applicability, units, assumptions and worked examples for each relation.
Worked exam-style examples
The four ways this section is written on the real exam — thoughts first, then equations, then substitution.
a relation matrix linking survey stations to control points Given rows (elements of the first set) (n_r) = 7.0000; columns (elements of the second set) (n_c) = 10.0000, determine the matrix entries (E) in entries.
Given
Find
matrix entries (E), in entries
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except E is given, so isolate E symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for E:
Step 3 — List the givens: rows (elements of the first set) (n_r) = 7.0000, columns (elements of the second set) (n_c) = 10.0000.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning E = 70.0000 entries to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 140.0 — kept a factor of two that cancels in the correct rearrangement.
- 35.0000 — dropped that same factor in the other direction.
- 77.0000 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a finite state machine transition table stored as a Boolean matrix Given matrix entries (E) = 381.0 entries; columns (elements of the second set) (n_c) = 9.0000, determine the rows (elements of the first set) (n_r).
Given
Find
rows (elements of the first set) (n_r)
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except n_r is given, so isolate n_r symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for n_r:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning n_r = 42.3333 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 84.6667 — kept a factor of two that cancels in the correct rearrangement.
- 21.1667 — dropped that same factor in the other direction.
- 46.5667 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a relation matrix linking pipe nodes to demand nodes Given matrix entries (E) = 180.0 entries; rows (elements of the first set) (n_r) = 13.0000, determine the columns (elements of the second set) (n_c).
Given
Find
columns (elements of the second set) (n_c)
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except n_c is given, so isolate n_c symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for n_c:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning n_c = 13.8462 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 27.6923 — kept a factor of two that cancels in the correct rearrangement.
- 6.9231 — dropped that same factor in the other direction.
- 15.2308 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a relation matrix linking survey stations to control points Given rows (elements of the first set) (n_r) = 19.0000; columns (elements of the second set) (n_c) = 8.0000, determine the matrix entries (E) in entries.
Given
Find
matrix entries (E), in entries
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except E is given, so isolate E symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for E:
Step 3 — List the givens: rows (elements of the first set) (n_r) = 19.0000, columns (elements of the second set) (n_c) = 8.0000.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning E = 152.0 entries to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 304.0 — kept a factor of two that cancels in the correct rearrangement.
- 76.0000 — dropped that same factor in the other direction.
- 167.2 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a finite state machine transition table stored as a Boolean matrix Given matrix entries (E) = 113.0 entries; columns (elements of the second set) (n_c) = 14.0000, determine the rows (elements of the first set) (n_r).
Given
Find
rows (elements of the first set) (n_r)
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except n_r is given, so isolate n_r symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for n_r:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning n_r = 8.0714 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 16.1429 — kept a factor of two that cancels in the correct rearrangement.
- 4.0357 — dropped that same factor in the other direction.
- 8.8786 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a relation matrix linking pipe nodes to demand nodes Given matrix entries (E) = 139.0 entries; rows (elements of the first set) (n_r) = 17.0000, determine the columns (elements of the second set) (n_c).
Given
Find
columns (elements of the second set) (n_c)
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except n_c is given, so isolate n_c symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for n_c:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning n_c = 8.1765 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 16.3529 — kept a factor of two that cancels in the correct rearrangement.
- 4.0882 — dropped that same factor in the other direction.
- 8.9941 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a relation matrix linking survey stations to control points Given rows (elements of the first set) (n_r) = 13.0000; columns (elements of the second set) (n_c) = 20.0000, determine the matrix entries (E) in entries.
Given
Find
matrix entries (E), in entries
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except E is given, so isolate E symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for E:
Step 3 — List the givens: rows (elements of the first set) (n_r) = 13.0000, columns (elements of the second set) (n_c) = 20.0000.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning E = 260.0 entries to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 520.0 — kept a factor of two that cancels in the correct rearrangement.
- 130.0 — dropped that same factor in the other direction.
- 286.0 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a finite state machine transition table stored as a Boolean matrix Given matrix entries (E) = 136.0 entries; columns (elements of the second set) (n_c) = 13.0000, determine the rows (elements of the first set) (n_r).
Given
Find
rows (elements of the first set) (n_r)
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except n_r is given, so isolate n_r symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for n_r:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning n_r = 10.4615 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 20.9231 — kept a factor of two that cancels in the correct rearrangement.
- 5.2308 — dropped that same factor in the other direction.
- 11.5077 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a relation matrix linking pipe nodes to demand nodes Given matrix entries (E) = 34.0000 entries; rows (elements of the first set) (n_r) = 6.0000, determine the columns (elements of the second set) (n_c).
Given
Find
columns (elements of the second set) (n_c)
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except n_c is given, so isolate n_c symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for n_c:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning n_c = 5.6667 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 11.3333 — kept a factor of two that cancels in the correct rearrangement.
- 2.8333 — dropped that same factor in the other direction.
- 6.2333 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)
a relation matrix linking survey stations to control points Given rows (elements of the first set) (n_r) = 6.0000; columns (elements of the second set) (n_c) = 15.0000, determine the matrix entries (E) in entries.
Given
Find
matrix entries (E), in entries
Start with the thinking
- The governing relation printed in this handbook section is Entries in a relation (adjacency) matrix.
- Everything except E is given, so isolate E symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- A relation between two finite sets is stored as a Boolean matrix of relation, so the storage cost is the entry count.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for E:
Step 3 — List the givens: rows (elements of the first set) (n_r) = 6.0000, columns (elements of the second set) (n_c) = 15.0000.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Step 6 — Check: returning E = 90.0000 entries to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 180.0 — kept a factor of two that cancels in the correct rearrangement.
- 45.0000 — dropped that same factor in the other direction.
- 99.0000 — rounded an intermediate value before the final step.
Reference: FE Handbook — Discrete Mathematics (Matrix of Relation)