Academia Aeternum
तमसो मा ज्योतिर्गमय
Wisdom · Knowledge · Eternity
MCQ Practice Arena
Count Favourable, Divide by Total — The Simplest Chapter with the Biggest Payoff
Probability is the highest-payoff chapter in Class X relative to study time — 6–8 Board marks achievable in 1–2 days. Every MCQ follows the same formula: P(E) = favourable outcomes / total outcomes. Problems on coins, dice, and playing cards account for 80% of questions; the patterns repeat across years. Use the complement rule to eliminate answer choices instantly.
Recall these cold before attempting MCQs — they appear in >70% of questions.
List the sample space for coins and single dice immediately — it takes 10 seconds and prevents errors. For two-dice MCQs, don't list all 36 outcomes — use systematic counting (sum = 7 has 6 outcomes: (1,6),(2,5),...). For card problems, memorise: 52 cards, 4 suits (13 each), 12 face cards (J, Q, K × 4), 4 aces, 26 red, 26 black. Use complement for "at least one" questions: 1 − P(none).
Work through each rung in order — do not jump to Hard before mastering Easy.
Basic formula, single coin/die, complement rule
Cards, two-dice sums, compound event probability
Conditional-style logic, "at least/at most" complement problems
CBSE — cards + dice; NTSE — logical probability reasoning