- A₹1,800
- B₹1,728
- C₹1,440
- D₹2,160
Step-by-Step Solution
Sailing time = 36/18 + 36/12 = 2 + 3 = 5 h. Fuel = L. Cost = 20 × ₹90 = ₹1,800. (₹1,728 uses 4.8 h, ignoring the current.)
Answer: A) ₹1,800
A ferry (15 km/h in still water) plies 36 km downstream and back on a river flowing at 3 km/h. Its engine burns 4 litres of diesel per hour of sailing, and diesel costs ₹90 a litre. What is the fuel cost of one round trip?
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