Question

Speed of a boat in still water to speed of boat in upstream is 8:5. If the boat can travel 440 km in downstream in 5 hours, then find the time taken by the boat to cover 32 km in still water.

A 30 minutes Correct Answer Incorrect Answer
B 20 minutes Correct Answer Incorrect Answer
C 15 minutes Correct Answer Incorrect Answer
D 18 minutes Correct Answer Incorrect Answer

Solution

Let speed of boat in still water and speed of boat in upstream be ‘8x’ km/h and ‘5x’ km/h, respectively. Speed of stream = 8x – 5x = 3x km/h Speed of boat in downstream = 8x + 3x = 11x km/h So, 11x = 440/5 = 88 Or, x = 8 Speed of boat in still water = 8 × 8 = 64 km/h Desired time = 32/64 = 30 minutes

Practice Next
×
×