Entrance Exams
Govt. Exams
B's rate = 1/24. A is 50% more efficient, so A's rate = 1.5 × (1/24) = 1.5/24 = 1/16. A takes 16 days.
Boat speed = (Downstream + Upstream) / 2 = (20 + 12) / 2 = 32 / 2 = 16 km/h.
After year 1: 1000 × 1.25 = 1250. After year 2: 1250 × 0.8 = 1000. Net change = 0% (returns to original price).
Speed = 200/5 = 40 km/h. Distance in 8 hours = 40 × 8 = 320 km.
Rate of pipe 1 = 1/15, Rate of pipe 2 = 1/20. Combined rate = 1/15 + 1/20 = 4/60 + 3/60 = 7/60. Time = 60/7 ≈ 8.57 minutes.
CP per article = 4000/100 = 40. CP of 60 articles = 2400, SP = 2400 × 1.1 = 2640. CP of 40 articles = 1600, SP = 1600 × 0.95 = 1520. Total SP = 2640 + 1520 = 4160. Profit = 4160 - 4000 = 160. Profit% = (160/4000) × 100 = 4%. But answer is B=2%. Rechecking: this should give 4%, not 2%. Let me verify the calculation once more. If answer should be B, there may be different problem parameters.
35% of x = 105. x = 105/0.35 = 300. 65% of 300 = 0.65 × 300 = 195.
B takes 30 days, so B's rate = 1/30. A works twice as fast, so A's rate = 2/30 = 1/15. Combined rate = 1/30 + 1/15 = 1/30 + 2/30 = 3/30 = 1/10. Time taken = 10 days.
Let x be invested at 12%, (5000-x) at 8%. 0.12x + 0.08(5000-x) = 520. 0.12x + 400 - 0.08x = 520. 0.04x = 120. x = 3000. Wait, let me recalculate: 0.12x + 0.08(5000-x) = 520. 12x + 8(5000-x) = 52000. 12x + 40000 - 8x = 52000. 4x = 12000. x = 3000. So answer should be C, not A. But given answer is A=2000. Let me verify with A: 0.12(2000) + 0.08(3000) = 240 + 240 = 480 ≠ 520. With C: 0.12(3000) + 0.08(2000) = 360 + 160 = 520. ✓ Correct answer is C=3000.
x% of 400 = 20% of 500. (x/100) × 400 = 0.2 × 500. 4x = 100. x = 25.