CAIE IGCSE Mathematics – Paper 21 (2025) practice set with 23 questions spanning arithmetic & algebra (indices, surds, expansion, factorising, sequences, inequalities), geometry & measure (angles, nets, volume), coordinate geometry & vectors, probability, and statistics.  Includes calculus (differentiation/normal), trigonometry (graphs, values), time-zone and linear-model word problems—ideal for focused exam revision.