Practice Dependency Graphs in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

A dependency graph is a directed graph where nodes are variables and arrows show which variables directly influence which others.

Like a flowchart: A affects B, B affects C. Arrows show dependencies.

Showing a random 20 of 50 problems.

Example 1

easy
In the chain A→B→C→D, how many ancestors does D have?

Example 2

easy
A graph has edges A→B, A→C, B→D. List the parents of D.

Example 3

medium
Find a valid evaluation order for C=A+B, E=C+D, where A,B,D are inputs.

Example 4

medium
Given A→B, A→C, B→D, C→D, D→E, list one valid topological order.

Example 5

easy
In a dependency graph, the edge X→Y means which variable directly influences the other?

Example 6

easy
Three tasks have the following dependencies: Task B depends on Task A, and Task C depends on Task B. Draw the dependency graph and determine a valid execution order.

Example 7

medium
Given D=A+B and E=D⋅C, list every variable that E depends on, directly or indirectly.

Example 8

easy
A formula computes C=A+B. Draw the dependency arrows.

Example 9

medium
Variables: rainfall → soil moisture → crop yield, and temperature → crop yield. If only temperature changes, does soil moisture change?

Example 10

easy
For z=f(x)+g(y), draw the dependency graph and identify the leaf node.

Example 11

medium
In the graph A→B, A→C, B→D, C→D, what is the out-degree of A?

Example 12

medium
Tasks A→B, A→C, B→D, C→D. What is the minimum number of stages to complete all tasks if independent tasks can run in parallel?

Example 13

easy
Does correlation between A and B guarantee that one depends on the other? Answer yes or no.

Example 14

easy
A node with no incoming arrows in a dependency graph is called a ____ variable.

Example 15

medium
In a causal dependency graph X→Y→Z, intervening on Y (forcing its value) breaks which arrow?

Example 16

medium
Given the dependencies: D depends on A and B; E depends on B and C; F depends on D and E. Find all valid topological orderings.

Example 17

challenge
A graph claims A→B, B→C, C→A is a valid computation pipeline. Identify the flaw and state the condition needed to fix it.

Example 18

medium
How many distinct topological orderings does the DAG A→B, A→C have? (No other edges.)

Example 19

medium
In the DAG with edges A→B, A→C, B→D, C→D, D→E, what is the longest path length (in edges) from A to E?

Example 20

medium
In a spreadsheet, cell C1=A1+B1 and D1=C1⋅2. If A1 changes, which cells must be recomputed?