Arithmetic Columns — Solution & ExplanationProblems / Arithmetic Columns / EditorialApproachSQL supports arithmetic directly in the SELECT clause.

revenue - cost computes profit per row.

(revenue - cost) / revenue * 100 computes the profit margin percentage.

ROUND(..., 2) rounds to 2 decimal places for clean output.

Derived columns like these are computed on-the-fly and don't modify the original table.Hints

You can use +, -, *, / directly on columns in SELECT.

Use parentheses to control the order of operations.

ROUND(value, 2) rounds to 2 decimal places.