{
  "title": "Ratios of Standard Angles (Trigonometry) - Grade 9 ICSE",
  "total_questions": 60,
  "questions": [
    {"id": 1, "difficulty": "easy", "question": "What is sin 30°? 📐", "options": {"A": "1/2", "B": "√3/2", "C": "1/√2", "D": "1"}, "correct_answer": "A"},
    {"id": 2, "difficulty": "easy", "question": "What is cos 60°? 🔺", "options": {"A": "√3/2", "B": "1/2", "C": "1", "D": "0"}, "correct_answer": "B"},
    {"id": 3, "difficulty": "easy", "question": "What is tan 45°? ⚖️", "options": {"A": "0", "B": "1", "C": "√3", "D": "1/√3"}, "correct_answer": "B"},
    {"id": 4, "difficulty": "easy", "question": "sin 0° = ? 🎯", "options": {"A": "1", "B": "0.5", "C": "0", "D": "√3/2"}, "correct_answer": "C"},
    {"id": 5, "difficulty": "easy", "question": "cos 90° = ? 📏", "options": {"A": "1", "B": "0.5", "C": "0", "D": "√3/2"}, "correct_answer": "C"},
    {"id": 6, "difficulty": "easy", "question": "tan 30° = ? 📉", "options": {"A": "1", "B": "√3", "C": "1/√3", "D": "√3/2"}, "correct_answer": "C"},
    {"id": 7, "difficulty": "easy", "question": "sin 45° = ? 🔷", "options": {"A": "1/2", "B": "1/√2", "C": "√3/2", "D": "1"}, "correct_answer": "B"},
    {"id": 8, "difficulty": "easy", "question": "cos 45° = ? 🔶", "options": {"A": "1/√2", "B": "1/2", "C": "√3/2", "D": "1"}, "correct_answer": "A"},
    {"id": 9, "difficulty": "easy", "question": "sin 60° = ? ⬆️", "options": {"A": "1/2", "B": "√3/2", "C": "1", "D": "1/√2"}, "correct_answer": "B"},
    {"id": 10, "difficulty": "easy", "question": "cos 30° = ? ⬇️", "options": {"A": "√3/2", "B": "1/2", "C": "1/√2", "D": "1"}, "correct_answer": "A"},
    {"id": 11, "difficulty": "easy", "question": "tan 60° = ? 📈", "options": {"A": "1", "B": "1/√3", "C": "√3", "D": "√3/2"}, "correct_answer": "C"},
    {"id": 12, "difficulty": "easy", "question": "sin 90° = ? 🎊", "options": {"A": "0", "B": "0.5", "C": "1", "D": "√3/2"}, "correct_answer": "C"},
    {"id": 13, "difficulty": "easy", "question": "cos 0° = ? 🎉", "options": {"A": "1", "B": "0", "C": "0.5", "D": "√3/2"}, "correct_answer": "A"},
    {"id": 14, "difficulty": "easy", "question": "What is 2 sin 30° cos 30°? ✖️", "options": {"A": "sin 60°", "B": "cos 60°", "C": "tan 60°", "D": "sin 30°"}, "correct_answer": "A"},
    {"id": 15, "difficulty": "easy", "question": "sin² 30° + cos² 30° = ? 🔢", "options": {"A": "0.5", "B": "0.75", "C": "1", "D": "1.25"}, "correct_answer": "C"},
    {"id": 16, "difficulty": "easy", "question": "tan 45° × cos 60° = ? 🤔", "options": {"A": "0.5", "B": "1", "C": "0.25", "D": "0.75"}, "correct_answer": "A"},
    {"id": 17, "difficulty": "easy", "question": "sin 30° + cos 60° = ? ➕", "options": {"A": "0.5", "B": "1", "C": "1.5", "D": "0.75"}, "correct_answer": "B"},
    {"id": 18, "difficulty": "easy", "question": "cos 45° × sin 45° = ? ✖️", "options": {"A": "0.25", "B": "0.5", "C": "0.75", "D": "1"}, "correct_answer": "B"},
    {"id": 19, "difficulty": "easy", "question": "tan 30° × tan 60° = ? 🔄", "options": {"A": "0.5", "B": "1", "C": "√3", "D": "3"}, "correct_answer": "B"},
    {"id": 20, "difficulty": "easy", "question": "sin 60° - sin 30° = ? ➖", "options": {"A": "(√3-1)/2", "B": "0.5", "C": "0.366", "D": "0.134"}, "correct_answer": "A"},
    
    {"id": 21, "difficulty": "medium", "question": "Value of sin 45° cos 45° + sin 30°? 🔢", "options": {"A": "0.5", "B": "0.75", "C": "1", "D": "1.25"}, "correct_answer": "B"},
    {"id": 22, "difficulty": "medium", "question": "4 sin 30° sin² 60° + 3 cos 60° tan 45° = ? 🤯", "options": {"A": "2", "B": "3", "C": "4", "D": "5"}, "correct_answer": "B"},
    {"id": 23, "difficulty": "medium", "question": "tan² 60° + 4 cos² 45° + 3 sec² 30° = ? 📊", "options": {"A": "10", "B": "12", "C": "14", "D": "16"}, "correct_answer": "B"},
    {"id": 24, "difficulty": "medium", "question": "If sin θ = 1/2, which θ from 0° to 90°? 🎯", "options": {"A": "30° only", "B": "60° only", "C": "30° or 150°", "D": "30° or 60°"}, "correct_answer": "A"},
    {"id": 25, "difficulty": "medium", "question": "cos θ = √3/2, then θ = ? 🔍", "options": {"A": "30°", "B": "45°", "C": "60°", "D": "90°"}, "correct_answer": "A"},
    {"id": 26, "difficulty": "medium", "question": "sin 60° cos 30° + cos 60° sin 30° = ? ➕✖️", "options": {"A": "sin 90°", "B": "cos 90°", "C": "sin 60°", "D": "1"}, "correct_answer": "A"},
    {"id": 27, "difficulty": "medium", "question": "2 tan 30°/(1 - tan² 30°) = ? ➗", "options": {"A": "tan 45°", "B": "tan 60°", "C": "tan 30°", "D": "sin 60°"}, "correct_answer": "B"},
    {"id": 28, "difficulty": "medium", "question": "cos 30° cos 45° - sin 30° sin 45° = ? ➖✖️", "options": {"A": "cos 75°", "B": "sin 75°", "C": "cos 15°", "D": "sin 15°"}, "correct_answer": "C"},
    {"id": 29, "difficulty": "medium", "question": "(tan 60° - tan 30°)/(1 + tan 60° tan 30°) = ? 📐", "options": {"A": "tan 30°", "B": "tan 45°", "C": "tan 60°", "D": "tan 90°"}, "correct_answer": "A"},
    {"id": 30, "difficulty": "medium", "question": "4/(cot² 30°) + 3 sin² 60° - 2 tan² 45° = ? 🧮", "options": {"A": "5", "B": "6", "C": "7", "D": "8"}, "correct_answer": "B"},
    {"id": 31, "difficulty": "medium", "question": "sin 30° cos 60° + cos 30° sin 60° = ? ➕", "options": {"A": "sin 90°", "B": "cos 90°", "C": "sin 60°", "D": "cos 60°"}, "correct_answer": "A"},
    {"id": 32, "difficulty": "medium", "question": "If 2 sin θ = √3, then θ = ? 🔎", "options": {"A": "30°", "B": "45°", "C": "60°", "D": "90°"}, "correct_answer": "C"},
    {"id": 33, "difficulty": "medium", "question": "cos 45°/(sec 30° + cosec 30°) = ? ➗", "options": {"A": "(√3-1)/2√2", "B": "(3-√3)/4", "C": "√3/4", "D": "1/4"}, "correct_answer": "B"},
    {"id": 34, "difficulty": "medium", "question": "2 cos² 45° + 3 tan² 30° - sin² 60° = ? 📈", "options": {"A": "1", "B": "1.5", "C": "2", "D": "2.5"}, "correct_answer": "A"},
    {"id": 35, "difficulty": "medium", "question": "sin(60°+θ) - sin(60°-θ) = ? 🔄", "options": {"A": "√3 sin θ", "B": "2 sin θ cos 60°", "C": "sin θ", "D": "2 cos θ sin 60°"}, "correct_answer": "C"},
    {"id": 36, "difficulty": "medium", "question": "tan 1° tan 2° ... tan 89° = ? 🤔", "options": {"A": "0", "B": "1", "C": "∞", "D": "Undefined"}, "correct_answer": "B"},
    {"id": 37, "difficulty": "medium", "question": "cos 1° cos 2° ... cos 90° = ? 🎯", "options": {"A": "0", "B": "1", "C": "0.5", "D": "∞"}, "correct_answer": "A"},
    {"id": 38, "difficulty": "medium", "question": "sin 25° cos 65° + cos 25° sin 65° = ? 🔄", "options": {"A": "0", "B": "0.5", "C": "1", "D": "√3/2"}, "correct_answer": "C"},
    {"id": 39, "difficulty": "medium", "question": "If tan θ = √3, then sin θ cos θ = ? ✖️", "options": {"A": "√3/4", "B": "1/4", "C": "3/4", "D": "1/2"}, "correct_answer": "A"},
    {"id": 40, "difficulty": "medium", "question": "3 tan² 45° - sin² 60° - ¼ cot² 30° + ⅛ sec² 45° = ? 🧮", "options": {"A": "1", "B": "1.25", "C": "1.5", "D": "1.75"}, "correct_answer": "C"},
    
    {"id": 41, "difficulty": "hard", "question": "sin⁶θ + cos⁶θ + 3 sin²θ cos²θ = ? 🎲", "options": {"A": "0", "B": "1", "C": "sin²θ + cos²θ", "D": "(sin²θ + cos²θ)³"}, "correct_answer": "B"},
    {"id": 42, "difficulty": "hard", "question": "tan 7° tan 23° tan 60° tan 67° tan 83° = ? 🔄", "options": {"A": "0", "B": "1", "C": "√3", "D": "1/√3"}, "correct_answer": "C"},
    {"id": 43, "difficulty": "hard", "question": "cos 20° cos 40° cos 60° cos 80° = ? ✖️", "options": {"A": "1/8", "B": "1/16", "C": "1/32", "D": "1/64"}, "correct_answer": "B"},
    {"id": 44, "difficulty": "hard", "question": "sin 10° sin 30° sin 50° sin 70° = ? 🤯", "options": {"A": "1/8", "B": "1/16", "C": "1/32", "D": "1/64"}, "correct_answer": "B"},
    {"id": 45, "difficulty": "hard", "question": "tan 6° tan 42° tan 66° tan 78° = ? 🔄", "options": {"A": "0", "B": "1", "C": "√3", "D": "1/√3"}, "correct_answer": "B"},
    {"id": 46, "difficulty": "hard", "question": "cos 36° cos 72° = ? 📐", "options": {"A": "1/8", "B": "1/4", "C": "1/2", "D": "√5/8"}, "correct_answer": "B"},
    {"id": 47, "difficulty": "hard", "question": "sin 18° = ? 🔍", "options": {"A": "(√5-1)/4", "B": "(√3-1)/2√2", "C": "(√5+1)/4", "D": "√(10-2√5)/4"}, "correct_answer": "A"},
    {"id": 48, "difficulty": "hard", "question": "cos 36° - cos 72° = ? ➖", "options": {"A": "1/2", "B": "1/4", "C": "1/8", "D": "√5/4"}, "correct_answer": "A"},
    {"id": 49, "difficulty": "hard", "question": "tan 75° + cot 75° = ? ➕", "options": {"A": "2", "B": "4", "C": "2√3", "D": "4√3"}, "correct_answer": "B"},
    {"id": 50, "difficulty": "hard", "question": "sin 75° - sin 15° = ? ➖", "options": {"A": "1/√2", "B": "√3/2", "C": "1/2", "D": "√2/2"}, "correct_answer": "A"},
    {"id": 51, "difficulty": "hard", "question": "cos 15° - √3 cos 75° = ? 🤔", "options": {"A": "0", "B": "1/2", "C": "√2/2", "D": "√3/2"}, "correct_answer": "C"},
    {"id": 52, "difficulty": "hard", "question": "tan 9° - tan 27° - tan 63° + tan 81° = ? ➖➕", "options": {"A": "0", "B": "2", "C": "4", "D": "8"}, "correct_answer": "C"},
    {"id": 53, "difficulty": "hard", "question": "sin 20° sin 40° sin 60° sin 80° = ? ✖️", "options": {"A": "3/16", "B": "√3/16", "C": "3√3/16", "D": "9/16"}, "correct_answer": "A"},
    {"id": 54, "difficulty": "hard", "question": "cos 20° + cos 100° + cos 140° = ? ➕", "options": {"A": "0", "B": "1", "C": "1/2", "D": "√3/2"}, "correct_answer": "A"},
    {"id": 55, "difficulty": "hard", "question": "tan 20° tan 40° tan 60° tan 80° = ? 🔄", "options": {"A": "1", "B": "√3", "C": "3", "D": "3√3"}, "correct_answer": "C"},
    {"id": 56, "difficulty": "hard", "question": "sin 10° sin 50° sin 70° = ? 📊", "options": {"A": "1/8", "B": "1/4", "C": "1/2", "D": "√3/8"}, "correct_answer": "A"},
    {"id": 57, "difficulty": "hard", "question": "cos 10° cos 30° cos 50° cos 70° = ? 🔄", "options": {"A": "√3/16", "B": "3/16", "C": "3√3/16", "D": "9/16"}, "correct_answer": "B"},
    {"id": 58, "difficulty": "hard", "question": "sin 6° sin 54° sin 66° = ? 🤯", "options": {"A": "1/8", "B": "1/4", "C": "1/2", "D": "√3/8"}, "correct_answer": "A"},
    {"id": 59, "difficulty": "hard", "question": "tan 50° + cot 50° = 2 cosec θ, then θ = ? 🔍", "options": {"A": "10°", "B": "20°", "C": "40°", "D": "80°"}, "correct_answer": "B"},
    {"id": 60, "difficulty": "hard", "question": "sin 47° + sin 61° - sin 11° - sin 25° = ? ➕➖", "options": {"A": "sin 36°", "B": "cos 36°", "C": "sin 72°", "D": "cos 72°"}, "correct_answer": "B"}
  ]
}