{
  "title": "Addition and Subtraction - Mixed Operations",
  "total_questions": 60,
  "questions": [
    {
      "id": 1,
      "difficulty": "Easy",
      "question": "2000 + 300 = ?",
      "options": { "A": "2200", "B": "2300", "C": "2400", "D": "2500" },
      "correct_answer": "B"
    },
    {
      "id": 2,
      "difficulty": "Easy",
      "question": "1500 - 500 = ?",
      "options": { "A": "900", "B": "1100", "C": "1000", "D": "1200" },
      "correct_answer": "C"
    },
    {
      "id": 3,
      "difficulty": "Easy",
      "question": "3000 + 400 = ?",
      "options": { "A": "3300", "B": "3400", "C": "3500", "D": "3600" },
      "correct_answer": "B"
    },
    {
      "id": 4,
      "difficulty": "Easy",
      "question": "5000 - 2000 = ?",
      "options": { "A": "4000", "B": "3500", "C": "3000", "D": "2800" },
      "correct_answer": "C"
    },
    {
      "id": 5,
      "difficulty": "Easy",
      "question": "600 + 3000 = ?",
      "options": { "A": "3400", "B": "3600", "C": "3200", "D": "3300" },
      "correct_answer": "B"
    },
    {
      "id": 6,
      "difficulty": "Easy",
      "question": "4500 - 1500 = ?",
      "options": { "A": "3500", "B": "3000", "C": "2800", "D": "2500" },
      "correct_answer": "B"
    },
    {
      "id": 7,
      "difficulty": "Easy",
      "question": "7000 + 200 = ?",
      "options": { "A": "7100", "B": "7200", "C": "7300", "D": "7400" },
      "correct_answer": "B"
    },
    {
      "id": 8,
      "difficulty": "Easy",
      "question": "4000 - 500 = ?",
      "options": { "A": "3500", "B": "3700", "C": "3800", "D": "3600" },
      "correct_answer": "A"
    },
    {
      "id": 9,
      "difficulty": "Easy",
      "question": "3500 + 300 = ?",
      "options": { "A": "3700", "B": "3800", "C": "3600", "D": "3900" },
      "correct_answer": "B"
    },
    {
      "id": 10,
      "difficulty": "Easy",
      "question": "2500 - 400 = ?",
      "options": { "A": "2100", "B": "2200", "C": "2300", "D": "2400" },
      "correct_answer": "A"
    },
    {
      "id": 11,
      "difficulty": "Easy",
      "question": "1500 + 100 = ?",
      "options": { "A": "1501", "B": "1700", "C": "1600", "D": "1650" },
      "correct_answer": "C"
    },
    {
      "id": 12,
      "difficulty": "Easy",
      "question": "9000 - 1000 = ?",
      "options": { "A": "7000", "B": "7500", "C": "8000", "D": "8500" },
      "correct_answer": "C"
    },
    {
      "id": 13,
      "difficulty": "Easy",
      "question": "4200 + 100 = ?",
      "options": { "A": "4300", "B": "4250", "C": "4100", "D": "4150" },
      "correct_answer": "A"
    },
    {
      "id": 14,
      "difficulty": "Easy",
      "question": "2700 - 700 = ?",
      "options": { "A": "1900", "B": "2000", "C": "2100", "D": "2200" },
      "correct_answer": "B"
    },
    {
      "id": 15,
      "difficulty": "Easy",
      "question": "3600 + 300 = ?",
      "options": {
        "A": "3800",
        "B": "3900",
        "C": "3700",
        "D": "3650"
      },
      "correct_answer": "B"
    },
    {
      "id": 16,
      "difficulty": "Easy",
      "question": "8400 - 400 = ?",
      "options": { "A": "8000", "B": "8200", "C": "8100", "D": "8300" },
      "correct_answer": "A"
    },
    {
      "id": 17,
      "difficulty": "Easy",
      "question": "2000 + 1500 = ?",
      "options": { "A": "3500", "B": "3400", "C": "3600", "D": "3300" },
      "correct_answer": "A"
    },
    {
      "id": 18,
      "difficulty": "Easy",
      "question": "5500 - 500 = ?",
      "options": { "A": "5200", "B": "5100", "C": "5000", "D": "4500" },
      "correct_answer": "C"
    },
    {
      "id": 19,
      "difficulty": "Easy",
      "question": "1100 + 900 = ?",
      "options": { "A": "1900", "B": "2000", "C": "1800", "D": "2100" },
      "correct_answer": "B"
    },
    {
      "id": 20,
      "difficulty": "Easy",
      "question": "7200 - 200 = ?",
      "options": { "A": "6900", "B": "7000", "C": "7100", "D": "7050" },
      "correct_answer": "B"
    },

    {
      "id": 21,
      "difficulty": "Medium",
      "question": "4500 + 2300 = ?",
      "options": { "A": "6700", "B": "6800", "C": "6900", "D": "7000" },
      "correct_answer": "B"
    },
    {
      "id": 22,
      "difficulty": "Medium",
      "question": "7800 - 3400 = ?",
      "options": { "A": "4300", "B": "4400", "C": "4500", "D": "4600" },
      "correct_answer": "B"
    },
    {
      "id": 23,
      "difficulty": "Medium",
      "question": "3250 + 1450 = ?",
      "options": { "A": "4600", "B": "4700", "C": "4800", "D": "4500" },
      "correct_answer": "B"
    },
    {
      "id": 24,
      "difficulty": "Medium",
      "question": "9000 - 4670 = ?",
      "options": {
        "A": "4230",
        "B": "4330",
        "C": "4420",
        "D": "4520"
      },
      "correct_answer": "B"
    },
    {
      "id": 25,
      "difficulty": "Medium",
      "question": "6540 + 230 = ?",
      "options": { "A": "6730", "B": "6770", "C": "6760", "D": "6800" },
      "correct_answer": "B"
    },
    {
      "id": 26,
      "difficulty": "Medium",
      "question": "5100 - 2600 = ?",
      "options": { "A": "2300", "B": "2400", "C": "2500", "D": "2600" },
      "correct_answer": "C"
    },
    {
      "id": 27,
      "difficulty": "Medium",
      "question": "4780 + 1200 = ?",
      "options": { "A": "5880", "B": "5980", "C": "6080", "D": "6180" },
      "correct_answer": "B"
    },
    {
      "id": 28,
      "difficulty": "Medium",
      "question": "8600 - 1700 = ?",
      "options": { "A": "6700", "B": "6800", "C": "6900", "D": "7000" },
      "correct_answer": "C"
    },
    {
      "id": 29,
      "difficulty": "Medium",
      "question": "3490 + 500 = ?",
      "options": { "A": "3990", "B": "3890", "C": "4090", "D": "4190" },
      "correct_answer": "A"
    },
    {
      "id": 30,
      "difficulty": "Medium",
      "question": "6000 - 3450 = ?",
      "options": {
        "A": "2450",
        "B": "2550",
        "C": "2600",
        "D": "2700"
      },
      "correct_answer": "B"
    },
    {
      "id": 31,
      "difficulty": "Medium",
      "question": "2100 + 3200 = ?",
      "options": { "A": "5200", "B": "5300", "C": "5100", "D": "5400" },
      "correct_answer": "B"
    },
    {
      "id": 32,
      "difficulty": "Medium",
      "question": "7800 - 1290 = ?",
      "options": { "A": "6510", "B": "6610", "C": "6710", "D": "6910" },
      "correct_answer": "A"
    },
    {
      "id": 33,
      "difficulty": "Medium",
      "question": "5200 + 430 = ?",
      "options": { "A": "5530", "B": "5630", "C": "5730", "D": "5830" },
      "correct_answer": "B"
    },
    {
      "id": 34,
      "difficulty": "Medium",
      "question": "9200 - 4800 = ?",
      "options": { "A": "4400", "B": "4200", "C": "4100", "D": "4300" },
      "correct_answer": "A"
    },
    {
      "id": 35,
      "difficulty": "Medium",
      "question": "6300 + 670 = ?",
      "options": { "A": "6870", "B": "6970", "C": "7070", "D": "7170" },
      "correct_answer": "B"
    },
    {
      "id": 36,
      "difficulty": "Medium",
      "question": "4000 - 1250 = ?",
      "options": { "A": "2750", "B": "2850", "C": "2950", "D": "3050" },
      "correct_answer": "A"
    },
    {
      "id": 37,
      "difficulty": "Medium",
      "question": "7890 + 100 = ?",
      "options": {
        "A": "8000",
        "B": "8010",
        "C": "8100",
        "D": "7990"
      },
      "correct_answer": "D"
    },
    {
      "id": 38,
      "difficulty": "Medium",
      "question": "5300 - 2700 = ?",
      "options": { "A": "2500", "B": "2600", "C": "2700", "D": "2800" },
      "correct_answer": "B"
    },
    {
      "id": 39,
      "difficulty": "Medium",
      "question": "6700 + 250 = ?",
      "options": { "A": "6850", "B": "6900", "C": "7020", "D": "6950" },
      "correct_answer": "D"
    },
    {
      "id": 40,
      "difficulty": "Medium",
      "question": "8100 - 3100 = ?",
      "options": { "A": "4900", "B": "5000", "C": "5050", "D": "5200" },
      "correct_answer": "B"
    },

    {
      "id": 41,
      "difficulty": "Hard",
      "question": "4567 + 2345 = ?",
      "options": { "A": "6792", "B": "6902", "C": "6912", "D": "7000" },
      "correct_answer": "C"
    },
    {
      "id": 42,
      "difficulty": "Hard",
      "question": "7890 - 4567 = ?",
      "options": { "A": "3210", "B": "3323", "C": "3400", "D": "3500" },
      "correct_answer": "B"
    },
    {
      "id": 43,
      "difficulty": "Hard",
      "question": "5000 + 3899 = ?",
      "options": { "A": "8899", "B": "8799", "C": "8800", "D": "8900" },
      "correct_answer": "A"
    },
    {
      "id": 44,
      "difficulty": "Hard",
      "question": "8000 - 2678 = ?",
      "options": { "A": "5222", "B": "5332", "C": "5422", "D": "5322" },
      "correct_answer": "D"
    },
    {
      "id": 45,
      "difficulty": "Hard",
      "question": "6789 + 2100 = ?",
      "options": { "A": "8789", "B": "8889", "C": "8900", "D": "8999" },
      "correct_answer": "B"
    },
    {
      "id": 46,
      "difficulty": "Hard",
      "question": "9500 - 4890 = ?",
      "options": { "A": "4610", "B": "4700", "C": "4600", "D": "4710" },
      "correct_answer": "A"
    },
    {
      "id": 47,
      "difficulty": "Hard",
      "question": "3456 + 6543 = ?",
      "options": { "A": "9999", "B": "10000", "C": "9990", "D": "10100" },
      "correct_answer": "A"
    },
    {
      "id": 48,
      "difficulty": "Hard",
      "question": "9876 - 5432 = ?",
      "options": { "A": "4333", "B": "4444", "C": "4555", "D": "4655" },
      "correct_answer": "B"
    },
    {
      "id": 49,
      "difficulty": "Hard",
      "question": "8765 + 1234 = ?",
      "options": { "A": "9999", "B": "10000", "C": "11000", "D": "9900" },
      "correct_answer": "A"
    },
    {
      "id": 50,
      "difficulty": "Hard",
      "question": "6000 - 1999 = ?",
      "options": { "A": "3901", "B": "4001", "C": "4010", "D": "4020" },
      "correct_answer": "B"
    },
    {
      "id": 51,
      "difficulty": "Hard",
      "question": "7899 + 1101 = ?",
      "options": { "A": "9000", "B": "8990", "C": "8900", "D": "9100" },
      "correct_answer": "A"
    },
    {
      "id": 52,
      "difficulty": "Hard",
      "question": "7654 - 2345 = ?",
      "options": { "A": "5209", "B": "5310", "C": "5309", "D": "5400" },
      "correct_answer": "C"
    },
    {
      "id": 53,
      "difficulty": "Hard",
      "question": "9990 + 10 = ?",
      "options": { "A": "10000", "B": "9999", "C": "10010", "D": "10020" },
      "correct_answer": "A"
    },
    {
      "id": 54,
      "difficulty": "Hard",
      "question": "6540 - 1765 = ?",
      "options": { "A": "4775", "B": "4780", "C": "4790", "D": "4800" },
      "correct_answer": "A"
    },
    {
      "id": 55,
      "difficulty": "Hard",
      "question": "8123 + 1877 = ?",
      "options": { "A": "10000", "B": "9990", "C": "11000", "D": "10100" },
      "correct_answer": "A"
    },
    {
      "id": 56,
      "difficulty": "Hard",
      "question": "9400 - 3500 = ?",
      "options": { "A": "5800", "B": "5900", "C": "6000", "D": "6200" },
      "correct_answer": "B"
    },
    {
      "id": 57,
      "difficulty": "Hard",
      "question": "4500 + 3499 = ?",
      "options": { "A": "7999", "B": "7800", "C": "7900", "D": "8000" },
      "correct_answer": "A"
    },
    {
      "id": 58,
      "difficulty": "Hard",
      "question": "7000 - 1234 = ?",
      "options": { "A": "5766", "B": "5666", "C": "5770", "D": "5780" },
      "correct_answer": "A"
    },
    {
      "id": 59,
      "difficulty": "Hard",
      "question": "6890 + 2100 = ?",
      "options": { "A": "8990", "B": "9000", "C": "9100", "D": "9200" },
      "correct_answer": "A"
    },
    {
      "id": 60,
      "difficulty": "Hard",
      "question": "9000 - 4321 = ?",
      "options": { "A": "4679", "B": "4680", "C": "4699", "D": "4700" },
      "correct_answer": "A"
    }
  ]
}