Example - under 18
Input
is_adult(16)
Output
False
16 is less than 18, so the function returns False.
Full lesson preview
Use Boolean Values
Learn how to produce and return boolean values using comparisons. Practice writing a simple condition that yields True or False.
Python practice6 minVariables & Data TypesBeginnerLast updated December 29, 2025
Problem statement
Write a function is_adult(age) that returns True if the given age is 18 or older, and False otherwise. Use a comparison expression to produce the boolean value directly.
Task
Implement a function that returns a boolean based on a numeric comparison (is age an adult?).
Examples
Example - exactly 18
Input
is_adult(18)
Output
True
Age 18 meets the threshold for being an adult, so the function returns True.
Input format
A single integer parameter: age (e.g., 17).
Output format
A boolean value: True or False.
Constraints
age is an integer between -1000 and 1000 (may be negative in edge cases).
Samples
Sample 1
Input
is_adult(20)
Output
True
20 is >= 18, so return True.