Adding both equations: 2x = 14, so x = 7. Alternatively, (x+y) + (x-y) = 10+4 gives 2x = 14

40% of 500 = 200. 25% of 200 = 50. Or (0.25 × 0.40 × 500) = 50

Boys:Girls = 3:5. If boys = 24, then 3x = 24, so x = 8. Girls = 5x = 5×8 = 40

Discount = 20% of 150 = 30. Selling price = 150 - 30 = Rs. 120

Area of square = side² = 7² = 49 cm²

∛512 = ∛(8³) = 8. Since 8 × 8 × 8 = 512

Distance = Speed × Time = 5 × 3.5 = 17.5 km

Total work = 8 × 12 = 96 worker-days. For 6 workers: 96/6 = 16 days

Sum of five numbers = 24 × 5 = 120. Sum of four numbers = 18+22+26+28 = 94. Fifth number = 120-94 = 26

Initial ratio milk:water = 60:40 = 3:2. Removing 20L mixture removes 12L milk and 8L water. New milk = 60-12+20 = 68L, water = 40-8 = 32L. Ratio = 68:32 = 17:8... Let me recalculate: Ratio = 60:40 simplified. After removing 20L (in ratio 3:2): milk 48, water 32. Add 20L milk: milk 68, water 32. Ratio = 68:32 = 17:8. Check options... Actually 68/32 ≈ 2.125, which is closer to 2:1 but let's verify: 68:32 = 17:8 (not matching). Actually should be approximately 3:1 range.