Quiz Discussion

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 boat covers a certain distance downstream in 1 hour, while it comes back in \(1\frac{1}{2}\) hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?

• 1] 12 kmph
• 2] 13 kmph
• 3] 14 kmph
• 4] 15 kmph
• 5] None of these

The speed of a boat along the stream is 12 km/hr and against the stream is 8 km/hr. The time taken by the boat to sail 24 km in still water is?

• 1] 2 hrs
• 2] 3 hrs
• 3] 2.4 hrs
• 4] 1.2 hrs

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 man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is:

• 1] 8.5 km/hr
• 2] 9 km/hr
• 3] 10 km/hr
• 4] 12.5 km/hr
• 5] None of these

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 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

• 2]

  5

• 3]

  6

• 4]

  10

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 boat can tarvel 36 km upstream in 5 hours. If the speed of the stream is 2.4 kmph, how much time will the boat take to cover a distance of 78 km downstream?(in hours)

• 1] 5 hours
• 2] 6.5 hours
• 3] 5.5 hours
• 4] 8 hours

A man rows 12 km in 5 hours against the stream and the speed of current being 4 kmph. What time will be taken by him to row 15 km with the stream?

• 1]

  1 hour \({ \text{27}}\frac{7}{{13}}\) minutes

• 2]

  1 hour \({ \text{24}}\frac{7}{{13}}\) minutes

• 3]

  1 hour \({ \text{25}}\frac{7}{{13}}\) minutes

• 4]

  1 hour \({ \text{26}}\frac{7}{{13}}\) minutes