3x3 table
Input
build_multiplication_table(3, 3)
Output
[[1, 2, 3], [2, 4, 6], [3, 6, 9]]
Rows and columns are 1-based. Row 2 column 3 = 2 * 3 = 6.
Full lesson preview
Build Multiplication Table
Generate a rows x cols multiplication table (1-based indices) as a list of lists.
Python practice17 minLoops & IterationIntermediateLast updated March 15, 2026
Problem statement
Write build_multiplication_table(rows, cols) that returns a list of rows lists, each containing cols integers. The value at row i and column j should be (i+1) * (j+1), using 1-based multiplication factors. If rows or cols are zero, return an empty list.
Task
Practice nested loops and building 2D lists row by row.
Examples
Input format
Two integers: rows and cols (each >= 0).
Output format
A list of lists representing the multiplication table.
Constraints
rows and cols are non-negative integers. Aim for O(rows * cols) time and space.
Samples
Sample 1
Input
build_multiplication_table(1, 4)
Output
[[1, 2, 3, 4]]
Single row with columns 1..4.