Geometric Progression (GP) has constant ratio r between consecutive terms. General term: aₙ = a × r^(n-1), where a = first term, r = common ratio. Example: 2, 6, 18, 54, ... has a=2, r=3. So a₅ = 2 × 3⁴ = 162. Identifying GP: Check if ratios are constant. Finding r: r = a₂/a₁. Finding nth term: aₙ = a × r^(n-1). Types: (1) r > 1: increasing GP; (2) 0 < r < 1: decreasing GP; (3) r < 0: alternating signs. Solving MCQs: (1) Find r from ratio; (2) Use formula; (3) Verify. Shortcut: Recognize common GPs (powers of 2, 3, etc.). Exam tip: Distinguish GP from AP. Handle negative r carefully (alternating terms).