{
  "title": "Addition and Subtraction - 4-Digit Subtraction",
  "total_questions": 60,
  "questions": [
    {
      "id": 1,
      "difficulty": "Easy",
      "question": "5000 - 2000 = ?",
      "options": { "A": "2000", "B": "3000", "C": "4000", "D": "2500" },
      "correct_answer": "B"
    },
    {
      "id": 2,
      "difficulty": "Easy",
      "question": "4000 - 1000 = ?",
      "options": { "A": "2000", "B": "2500", "C": "3000", "D": "3500" },
      "correct_answer": "C"
    },
    {
      "id": 3,
      "difficulty": "Easy",
      "question": "3500 - 1500 = ?",
      "options": { "A": "2000", "B": "1500", "C": "1800", "D": "1700" },
      "correct_answer": "A"
    },
    {
      "id": 4,
      "difficulty": "Easy",
      "question": "2200 - 1200 = ?",
      "options": { "A": "900", "B": "1000", "C": "1100", "D": "1200" },
      "correct_answer": "B"
    },
    {
      "id": 5,
      "difficulty": "Easy",
      "question": "3000 - 500 = ?",
      "options": { "A": "2600", "B": "2500", "C": "2700", "D": "2800" },
      "correct_answer": "B"
    },
    {
      "id": 6,
      "difficulty": "Easy",
      "question": "2800 - 800 = ?",
      "options": { "A": "1800", "B": "1900", "C": "2000", "D": "2100" },
      "correct_answer": "C"
    },
    {
      "id": 7,
      "difficulty": "Easy",
      "question": "4500 - 2500 = ?",
      "options": { "A": "1500", "B": "1800", "C": "2000", "D": "1600" },
      "correct_answer": "C"
    },
    {
      "id": 8,
      "difficulty": "Easy",
      "question": "6000 - 3000 = ?",
      "options": { "A": "2000", "B": "2500", "C": "3000", "D": "3500" },
      "correct_answer": "C"
    },
    {
      "id": 9,
      "difficulty": "Easy",
      "question": "7000 - 2000 = ?",
      "options": { "A": "4000", "B": "4500", "C": "5000", "D": "6000" },
      "correct_answer": "C"
    },
    {
      "id": 10,
      "difficulty": "Easy",
      "question": "5200 - 1200 = ?",
      "options": { "A": "3800", "B": "4000", "C": "4200", "D": "3000" },
      "correct_answer": "B"
    },
    {
      "id": 11,
      "difficulty": "Easy",
      "question": "3400 - 1400 = ?",
      "options": { "A": "2200", "B": "2000", "C": "1800", "D": "2100" },
      "correct_answer": "B"
    },
    {
      "id": 12,
      "difficulty": "Easy",
      "question": "4800 - 1800 = ?",
      "options": { "A": "2000", "B": "2900", "C": "3000", "D": "3200" },
      "correct_answer": "C"
    },
    {
      "id": 13,
      "difficulty": "Easy",
      "question": "2900 - 900 = ?",
      "options": { "A": "2000", "B": "2100", "C": "2200", "D": "2300" },
      "correct_answer": "A"
    },
    {
      "id": 14,
      "difficulty": "Easy",
      "question": "1500 - 700 = ?",
      "options": { "A": "700", "B": "800", "C": "900", "D": "1000" },
      "correct_answer": "B"
    },
    {
      "id": 15,
      "difficulty": "Easy",
      "question": "8000 - 1000 = ?",
      "options": { "A": "6000", "B": "7000", "C": "6500", "D": "6800" },
      "correct_answer": "B"
    },
    {
      "id": 16,
      "difficulty": "Easy",
      "question": "2300 - 1300 = ?",
      "options": { "A": "800", "B": "900", "C": "1000", "D": "1100" },
      "correct_answer": "C"
    },
    {
      "id": 17,
      "difficulty": "Easy",
      "question": "3600 - 600 = ?",
      "options": { "A": "2800", "B": "2900", "C": "3000", "D": "3200" },
      "correct_answer": "C"
    },
    {
      "id": 18,
      "difficulty": "Easy",
      "question": "9000 - 4000 = ?",
      "options": { "A": "4000", "B": "4500", "C": "5000", "D": "5500" },
      "correct_answer": "C"
    },
    {
      "id": 19,
      "difficulty": "Easy",
      "question": "4200 - 200 = ?",
      "options": { "A": "3900", "B": "4000", "C": "4100", "D": "4200" },
      "correct_answer": "B"
    },
    {
      "id": 20,
      "difficulty": "Easy",
      "question": "5100 - 3100 = ?",
      "options": { "A": "1800", "B": "1900", "C": "2000", "D": "2100" },
      "correct_answer": "C"
    },

    {
      "id": 21,
      "difficulty": "Medium",
      "question": "4321 - 1234 = ?",
      "options": { "A": "3000", "B": "3087", "C": "3100", "D": "2999" },
      "correct_answer": "B"
    },
    {
      "id": 22,
      "difficulty": "Medium",
      "question": "5600 - 2300 = ?",
      "options": { "A": "3200", "B": "3300", "C": "3400", "D": "3500" },
      "correct_answer": "B"
    },
    {
      "id": 23,
      "difficulty": "Medium",
      "question": "7890 - 2345 = ?",
      "options": { "A": "5545", "B": "5445", "C": "5655", "D": "5535" },
      "correct_answer": "A"
    },
    {
      "id": 24,
      "difficulty": "Medium",
      "question": "6450 - 1200 = ?",
      "options": { "A": "5250", "B": "5350", "C": "5150", "D": "5050" },
      "correct_answer": "A"
    },
    {
      "id": 25,
      "difficulty": "Medium",
      "question": "5000 - 2750 = ?",
      "options": { "A": "2250", "B": "2350", "C": "2150", "D": "2100" },
      "correct_answer": "A"
    },
    {
      "id": 26,
      "difficulty": "Medium",
      "question": "7100 - 3900 = ?",
      "options": { "A": "3100", "B": "3200", "C": "3300", "D": "3000" },
      "correct_answer": "B"
    },
    {
      "id": 27,
      "difficulty": "Medium",
      "question": "9999 - 5555 = ?",
      "options": { "A": "4444", "B": "4454", "C": "4464", "D": "4434" },
      "correct_answer": "A"
    },
    {
      "id": 28,
      "difficulty": "Medium",
      "question": "6800 - 2700 = ?",
      "options": { "A": "4100", "B": "4000", "C": "3900", "D": "4200" },
      "correct_answer": "A"
    },
    {
      "id": 29,
      "difficulty": "Medium",
      "question": "8500 - 1250 = ?",
      "options": { "A": "7350", "B": "7250", "C": "7450", "D": "7550" },
      "correct_answer": "B"
    },
    {
      "id": 30,
      "difficulty": "Medium",
      "question": "6123 - 2123 = ?",
      "options": { "A": "3800", "B": "3900", "C": "4000", "D": "4200" },
      "correct_answer": "C"
    },
    {
      "id": 31,
      "difficulty": "Medium",
      "question": "4780 - 1780 = ?",
      "options": { "A": "2900", "B": "3000", "C": "3100", "D": "2800" },
      "correct_answer": "B"
    },
    {
      "id": 32,
      "difficulty": "Medium",
      "question": "7200 - 3400 = ?",
      "options": { "A": "3600", "B": "3700", "C": "3800", "D": "3900" },
      "correct_answer": "C"
    },
    {
      "id": 33,
      "difficulty": "Medium",
      "question": "5400 - 4300 = ?",
      "options": { "A": "900", "B": "1000", "C": "1100", "D": "1200" },
      "correct_answer": "C"
    },
    {
      "id": 34,
      "difficulty": "Medium",
      "question": "8100 - 4500 = ?",
      "options": { "A": "3600", "B": "3500", "C": "3700", "D": "3800" },
      "correct_answer": "A"
    },
    {
      "id": 35,
      "difficulty": "Medium",
      "question": "9500 - 5500 = ?",
      "options": { "A": "3900", "B": "4000", "C": "4200", "D": "4300" },
      "correct_answer": "B"
    },
    {
      "id": 36,
      "difficulty": "Medium",
      "question": "6200 - 4100 = ?",
      "options": { "A": "1800", "B": "2000", "C": "2100", "D": "2200" },
      "correct_answer": "C"
    },
    {
      "id": 37,
      "difficulty": "Medium",
      "question": "7890 - 2890 = ?",
      "options": { "A": "4900", "B": "5000", "C": "5100", "D": "5200" },
      "correct_answer": "B"
    },
    {
      "id": 38,
      "difficulty": "Medium",
      "question": "8900 - 5600 = ?",
      "options": { "A": "3200", "B": "3300", "C": "3400", "D": "3500" },
      "correct_answer": "B"
    },
    {
      "id": 39,
      "difficulty": "Medium",
      "question": "4800 - 3900 = ?",
      "options": { "A": "800", "B": "900", "C": "1000", "D": "1100" },
      "correct_answer": "B"
    },
    {
      "id": 40,
      "difficulty": "Medium",
      "question": "9999 - 1111 = ?",
      "options": { "A": "8889", "B": "8998", "C": "8888", "D": "8890" },
      "correct_answer": "C"
    },

    {
      "id": 41,
      "difficulty": "Hard",
      "question": "8650 - 4321 = ?",
      "options": { "A": "4329", "B": "4339", "C": "4349", "D": "4319" },
      "correct_answer": "A"
    },
    {
      "id": 42,
      "difficulty": "Hard",
      "question": "9999 - 6789 = ?",
      "options": { "A": "3111", "B": "3222", "C": "3333", "D": "3210" },
      "correct_answer": "D"
    },
    {
      "id": 43,
      "difficulty": "Hard",
      "question": "7894 - 5678 = ?",
      "options": { "A": "2100", "B": "2216", "C": "2316", "D": "2236" },
      "correct_answer": "B"
    },
    {
      "id": 44,
      "difficulty": "Hard",
      "question": "7000 - 3456 = ?",
      "options": { "A": "3454", "B": "3544", "C": "3554", "D": "3560" },
      "correct_answer": "B"
    },
    {
      "id": 45,
      "difficulty": "Hard",
      "question": "8567 - 4567 = ?",
      "options": { "A": "3990", "B": "4000", "C": "4100", "D": "4200" },
      "correct_answer": "B"
    },
    {
      "id": 46,
      "difficulty": "Hard",
      "question": "6789 - 1234 = ?",
      "options": { "A": "5555", "B": "5565", "C": "5575", "D": "5585" },
      "correct_answer": "A"
    },
    {
      "id": 47,
      "difficulty": "Hard",
      "question": "9123 - 3210 = ?",
      "options": { "A": "5913", "B": "5923", "C": "5933", "D": "5943" },
      "correct_answer": "A"
    },
    {
      "id": 48,
      "difficulty": "Hard",
      "question": "8000 - 2789 = ?",
      "options": { "A": "5200", "B": "5211", "C": "5300", "D": "5311" },
      "correct_answer": "B"
    },
    {
      "id": 49,
      "difficulty": "Hard",
      "question": "7000 - 4890 = ?",
      "options": { "A": "2110", "B": "2200", "C": "2210", "D": "2300" },
      "correct_answer": "A"
    },
    {
      "id": 50,
      "difficulty": "Hard",
      "question": "6000 - 2345 = ?",
      "options": { "A": "3655", "B": "3665", "C": "3675", "D": "3680" },
      "correct_answer": "A"
    },
    {
      "id": 51,
      "difficulty": "Hard",
      "question": "7890 - 4890 = ?",
      "options": { "A": "2990", "B": "3000", "C": "3100", "D": "3200" },
      "correct_answer": "B"
    },
    {
      "id": 52,
      "difficulty": "Hard",
      "question": "9500 - 6789 = ?",
      "options": { "A": "2601", "B": "2711", "C": "2721", "D": "2731" },
      "correct_answer": "B"
    },
    {
      "id": 53,
      "difficulty": "Hard",
      "question": "8765 - 2345 = ?",
      "options": { "A": "6320", "B": "6400", "C": "6420", "D": "6410" },
      "correct_answer": "C"
    },
    {
      "id": 54,
      "difficulty": "Hard",
      "question": "6978 - 1987 = ?",
      "options": { "A": "4881", "B": "4991", "C": "5001", "D": "5101" },
      "correct_answer": "B"
    },
    {
      "id": 55,
      "difficulty": "Hard",
      "question": "5432 - 3210 = ?",
      "options": { "A": "2100", "B": "2222", "C": "2232", "D": "2300" },
      "correct_answer": "B"
    },
    {
      "id": 56,
      "difficulty": "Hard",
      "question": "9000 - 678 = ?",
      "options": { "A": "8300", "B": "8322", "C": "8400", "D": "8321" },
      "correct_answer": "B"
    },
    {
      "id": 57,
      "difficulty": "Hard",
      "question": "7654 - 4321 = ?",
      "options": { "A": "3333", "B": "3343", "C": "3353", "D": "3363" },
      "correct_answer": "A"
    },
    {
      "id": 58,
      "difficulty": "Hard",
      "question": "8888 - 4444 = ?",
      "options": { "A": "4333", "B": "4444", "C": "4555", "D": "4666" },
      "correct_answer": "B"
    },
    {
      "id": 59,
      "difficulty": "Hard",
      "question": "9999 - 2222 = ?",
      "options": { "A": "7555", "B": "7677", "C": "7777", "D": "7877" },
      "correct_answer": "C"
    },
    {
      "id": 60,
      "difficulty": "Hard",
      "question": "8000 - 1234 = ?",
      "options": { "A": "6666", "B": "6766", "C": "6776", "D": "6786" },
      "correct_answer": "B"
    }
  ]
}