Types include: (1) Duplicate ratio (a:b squared = a²:b²); (2) Triplicate ratio (a:b cubed = a³:b³); (3) Sub-duplicate/Square root ratio (√a:√b); (4) Sub-triplicate/Cube root ratio (∛a:∛b); (5) Compound ratio (product of multiple ratios). Example: If a:b = 2:3 and b:c = 5:7, compound ratio a:c = (2×5):(3×7) = 10:21. Solving approach: Identify ratio type from keywords (squared, cubed, roots). For compound ratios, multiply corresponding terms. Shortcut: Use factorization for complex ratios. Exam tip: Distinguish between duplicate and compound ratios carefully. Focus on MCQ patterns involving multiple ratio relationships.