Question 59

A boat takes a total time of eight hours to travel 63 kms upstream and the same distance downstream. The speed of the current is $${1 \over 8}$$th of the speed of the boat in still water. What is the speed of the boat in still water? (in km/hr)

Solution

Let speed of current = $$x$$ km/hr

=> Speed of boat in still water = $$8x$$ km/hr

Acc. to ques, => $$\frac{63}{9x} + \frac{63}{7x} = 8$$

=> $$\frac{7}{x} + \frac{9}{x} = 8$$

=> $$\frac{16}{x} = 8$$

=> $$x = \frac{16}{8} = 2$$

$$\therefore$$ Speed of boat in still water = $$8 \times 2 = 16$$ km/hr

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: