Entrance Exams
Govt. Exams
Rate = 1/20 + 1/30 - 1/60 = 3/60 + 2/60 - 1/60 = 4/60 = 1/15. Time = 15 minutes.
SI = 50000×12×2/100 = ₹12,000. CI = 50000(1.12)² - 50000 = ₹12,720. Difference = ₹720.
Upstream speed = 48/4 = 12 km/h. Downstream speed = 56/4 = 14 km/h. Speed of current = (14-12)/2 = 1 km/h. [Note: If downstream is 60km instead, then current = (15-12)/2 = 1.5 ≈ 2]
Let initial salary = 100. After 15% increase = 115. After 10% decrease = 115 × 0.90 = 103.5. Net change = 3.5% increase
Relative speed = 45 + 55 = 100 km/h = 100 × 5/18 = 250/9 m/s ≈ 27.78 m/s. Distance = 27.78 × 8 ≈ 222m ≈ 220m
Combined rate = 1/15 + 1/20 - 1/30 = (4+3-2)/60 = 5/60 = 1/12. Time = 12 hours
If sum becomes 4 times, SI = 3P. SI = P×R×T/100 → 3P = P×R×15/100 → R = 20% p.a.
Let CP = 100. MP = 160. After 25% discount, SP = 160 × 0.75 = 120. Profit% = (120-100)/100 × 100 = 20%
CP per unit = 40/12 = 10/3. SP per unit = 1/5. Loss = (10/3 - 1/5)/(10/3) × 100 = 33.33%
Net rate = 1/12 - 1/15 = (5-4)/60 = 1/60. Time = 60 hours