Govt. Exams
Entrance Exams
Speed = 200/5 = 40 km/h. Distance in 8 hours = 40 × 8 = 320 km.
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.
x% of 400 = 20% of 500. (x/100) × 400 = 0.2 × 500. 4x = 100. x = 25.
Let CP = 100. MP = 160. After 25% discount, SP = 160 × 0.75 = 120. Profit = 120 - 100 = 20. Profit% = 20%.
A = P(1 + R/100)^T = 12000(1.1)^2 = 12000 × 1.21 = 14,520.
SI = P × R × T / 100. 1200 = P × 8 × 3 / 100. P = (1200 × 100) / 24 = 5000.
Original time = 480/60 = 8 hours. New speed = 72 km/h. New time = 480/72 = 6.67 hours. Time saved = 8 - 6.67 = 1.33 ≈ 1 hour (approximately 1 hour 20 minutes).
When a number undergoes multiple percentage changes, we must apply each change sequentially to find the net effect.
Step 1: Apply the 40% Increase
Starting with an original number, a 40% increase multiplies it by 1.40.
Step 2: Apply the 30% Decrease
A 30% decrease means we retain 70% of the value, so we multiply by 0.70.
Step 3: Calculate Net Change
The final value is 0.98x, which is 98% of the original value x.
The net change is a 2% decrease. Answer: (B)
Discount = 30% of 1000 = 300. Selling price = 1000 - 300 = Rs. 700
