Ratio and proportion word problems require translating English into mathematical expressions. Common types: (1) Age problems using ratios; (2) Work/time problems; (3) Mixture problems with ratios; (4) Profit/loss sharing. Solving approach: (1) Define variables as ratio parts (a:b means ax and bx); (2) Set up equation from given condition; (3) Solve for multiplier; (4) Find actual values. Example: A:B age ratio 3:4, A is 12 years old. Then 3x = 12, x = 4, B = 4x = 16. Shortcut: Use ratio notation directly without expanding initially. Exam tip: Read carefully for comparative statements ('more than', 'less than', 'thrice'). Always state answer with proper units and verify reasonableness.