Practice Dependent vs Independent Variables in Math

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

Quick Recap

The independent variable is chosen freely as input; the dependent variable's value is then determined by the function rule.

You choose the input (independent), and the function gives the output (dependent).

Showing a random 20 of 50 problems.

Example 1

hard
In y=12x, describe how the dependent variable responds as the independent variable triples.

Example 2

medium
Given y=3x−1, find the dependent value when the independent value is 4.

Example 3

medium
On a graph, which axis typically shows the independent variable?

Example 4

easy
In the equation d=60t (distance = speed × time), which is dependent?

Example 5

easy
In A=πr2, what is the independent variable?

Example 6

medium
In x=5−2y, if y is independent, express the dependent variable explicitly.

Example 7

easy
A water tank fills at a constant rate, V=5t (liters at time t minutes). Which is dependent?

Example 8

easy
In y=4x−7, name the dependent variable.

Example 9

medium
A taxi charges 3plus2 per mile: C=3+2m. Identify both variables and their roles.

Example 10

medium
In the data table input 1,2,3 → output 2,4,6, name the variables.

Example 11

challenge
A circle's area depends on radius. If the radius is the independent variable, find the rate-style ratio Ar2 and explain.

Example 12

challenge
Two quantities satisfy y=mx for unknown fixed m. Using the point (2,6), find m, then state which symbol is the parameter.

Example 13

medium
A scientist plots height versus age. Which axis holds age?

Example 14

challenge
In P=kV (fixed k), describe how the dependent variable responds as the independent one doubles.

Example 15

medium
If y depends on x via y=−2x+6, what happens to y when x increases by 1?

Example 16

challenge
A car's stopping distance is d=0.05v2 in meters. If a driver doubles their speed, by what factor does the dependent value d grow?

Example 17

medium
For a table with inputs 1,2,3,4 giving outputs 5,8,11,14, write the linear rule with x independent.

Example 18

medium
A coffee shop's daily revenue R depends on customers n: R=4.5n. Find n when R=270.

Example 19

medium
A phone plan costs C=30+0.10m dollars, where m is minutes used. Identify both variables and find C when m=200.

Example 20

easy
In h=2+3d where d is days, find the dependent value when d=4.