Entrance Exams
Govt. Exams
100 × 1.20 × 0.90 = 108. Net increase = 8%
SI = (P × R × T)/100 = (8000 × 7.5 × 4)/100 = 240000/100 = Rs. 2400
Selling Price = 2000 × (1 - 0.15) = 2000 × 0.85 = Rs. 1700
Original = 100. After 25% increase = 125. After 20% decrease = 125 × 0.80 = 100. Net change = (100-100)/100 = 0%. Wait, recalculate: 125 × 0.80 = 100. Actually net is 0%. Correction: 100 × 1.25 × 0.80 = 100. Let me verify: 100 → 125 → 100. Net = 0%. Rechecking: 1.25 × 0.80 = 1.00. Net change = 0%.
Profit = (1.40 × 0.90 - 1) × 100 = 1.26 - 1 = 0.26 = 26%
SI = (P × R × T)/100 = (1000 × 8 × 2)/100 = Rs. 160.
Downstream speed = boat speed + stream speed = 15 + 3 = 18 km/h.
Relative speed = 40 + 50 = 90 km/h = 25 m/s. Total distance = 120 + 180 = 300m. Time = 300/25 = 12 seconds. [Recalc: 12 seconds should match option C. Time = 300/25 = 12 seconds]
Net rate = 1/12 - 1/18 = 3/36 - 2/36 = 1/36. Time = 36 hours.
A's work rate = 1/15, B's rate = 1/20. Combined = 1/15 + 1/20 = 7/60. Time = 60/7 ≈ 8.57 days.