Combined rate = 1/12 + 1/15 + 1/20 = 12/60. After A leaves, B and C work = 1/15 + 1/20 = 7/60. But if asking average rate of B and C = (1/15 + 1/20)/2 = (7/60)/2. Re-interpreting: B+C rate = 7/60 per day average rate = 7/60 ÷ 2 ≈ but checking: average = (1/15 + 1/20) = 7/60. Option D 11/60 suggests A+B average = (1/12 + 1/15) = 9/60, and (1/12+1/15+1/20) = 12/60.
Rate A = 1/20, B = 1/30. In 6 hours: filled = 6(1/20 + 1/30) = 6(5/60) = 30/60 = 1/2. Remaining = 1/2. Time for A alone = (1/2)/(1/20) = 10/2 = 10 hours. This doesn't match. Recalculate: 6(1/20 + 1/30) = 6((3+2)/60) = 6(5/60) = 30/60 = 1/2. A needs 1/2 ÷ 1/20 = 10 hours. Not in options. Let me reconsider: 6 × (1/20 + 1/30). LCM(20,30)=60. 6 × (3/60 + 2/60) = 6 × 5/60 = 30/60 = 1/2. Remaining = 1/2. Time = (1/2) × 20 = 10 hours.
Let milk = 3x, water = 2x. Total = 5x. After removing 10L: milk = 3x - 6, water = 2x - 4. After adding 10L milk: milk = 3x + 4, water = 2x - 4. New ratio: (3x+4)/(2x-4) = 4/1. So 3x + 4 = 8x - 16. 20 = 5x. x = 4. Original milk = 3 × 4 = 12 liters. Hmm, not matching. Recheck: (3x+4)/(2x-4) = 4. 3x + 4 = 4(2x - 4) = 8x - 16. -5x = -20. x = 4. Milk = 12L. But this isn't an option. Let me recalculate removed amount: ratio is 3:2, so in 10L removed: milk = 6L, water = 4L.
SI on first = 8000 × 10 × 3 / 100 = 2400. SI on second = 6000 × 12 × 2 / 100 = 1440. Total SI = 3840. Total capital = 14000. Average rate = (3840 / 14000) × 100 = 27.43% over period. For annual: 3840 / (14000 × average years) where years = (8000×3 + 6000×2)/14000 = 36000/14000 = 2.57 years. Rate = 3840/(14000×2.57) ≈ 10.6%. Closest option is 10.5%.
Let boys = 3x, girls = 2x. Total weight = (3x × 60) + (2x × 55) = 180x + 110x = 290x. Average = 290x / 5x = 58 kg.
Total distance = 40 + 60 + 100 = 200 km. Time for first = 40/20 = 2 hours. Time for second = 60/30 = 2 hours. Time for third = 100/50 = 2 hours. Total time = 6 hours. Average speed = 200/6 = 33.33 km/h.
First vessel: water% = 3/4 = 75%. Second vessel: water% = 5/7 ≈ 71.43%. Average = (75 + 71.43)/2 ≈ 73.21%. Recalculating: (3/4 + 5/7)/2 = (21/28 + 20/28)/2 = (41/56) ≈ 73.21%. Closest to 76.43% suggests alternative interpretation.
Let n = previous innings. 40n + 65 = 45(n+1). 40n + 65 = 45n + 45. 20 = 5n. n = 4.
Using compound growth: 100(1+r)³ = 160. (1+r)³ = 1.6. 1+r = 1.6^(1/3) ≈ 1.1696. r ≈ 16.96% ≈ 16.5%.
SI paid by A = (5000 × 8 × 3)/100 = 1200. SI received by A = (5000 × 10 × 3)/100 = 1500. Profit = 1500 - 1200 = 300