Quiz Discussion

The speed of a boat downstream is 15 km/hr and the speed of current is 3 km/hr. Find the total time taken by the boat to cover 15 km upstream and 15 km downstream.

• 1] 2 hours 40 minutes
• 2] 2 hours 42 minutes
• 3] 2 hours 10 minutes
• 4] 2 hours 30 minutes

A man can row three quarters of a kilometers against the stream in 11 1/4 minutes and return in 7 1/2​ minutes.The speed of the man in still water is

• 1]

  2 km/h

• 2]

  3 km/h

• 3]

  4 km/h

• 4]

  5 km/h

A boat moves downstream at the rate of 1 km in \({ \text{7}}\frac{1}{2}\) minutes and upstream at the rate of 5 km an hour. What is the speed of the boat in the still water?

• 1]

  8 km/hour

• 2]

  \({ \text{6}}\frac{1}{2}\) km/hour

• 3]

  4 km/hour

• 4]

  \({ \text{3}}\frac{1}{2}\) km/hour

A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:

• 1] 2 mph
• 2] 2.5 mph
• 3] 3 mph
• 4] 4 mph
• 5] None of these

A motorboat, whose speed in 15 km/hr in still water goes 30 km downstream and comes back in a total of 4 hours 30 minutes. The speed of the stream (in km/hr) is:

• 1] 4 km/hr
• 2] 5 km/hr
• 3] 6 km/hr
• 4] 10 km/hr

A boat takes half time in moving a certain distance downstream than upstream. The ratio of the speed of the boat in still water and that of the current is?

• 1] 2 : 1
• 2] 4 : 3
• 3] 1 : 2
• 4] 3 : 1

A man can row three-quarters of a kilometer against the stream in \(11\frac{1}{4}\) minutes and down the stream in \(7\frac{1}{2}\) minutes. The speed (in km/hr) of the man in still water is:

• 1] 2
• 2] 3
• 3] 4
• 4] 5

A man can row upstream at 12km/hr and downstream at 18 km/hr. The man rowing speed in still water is?

• 1] 15 km/hr
• 2] 5 km/hr
• 3] 3 km/hr
• 4] 10 km/hr

a man can row 8 km/hr in still water and he find that it takes thrice as long to row upstream as to row downstream to the same point. What is the speed of the current?

• 1]

  1 kmph

• 2]

  2 kmph

• 3]

  3 kmph

• 4]

  4 kmph

If the speed of a boat in still water is 20km/hr and the speed of the current is 5km, then the time taken by the boat to travel 100 km with the current is?

• 1] 2 hours
• 2] 3 hours
• 3] 4 hours
• 4] 7 hours