Quiz Discussion

A boat while dowenstream in a reiver converd a distance of 50 miles at an average speed of 60 miles per hour. While returning , because of the water resistance , it took 1 hour 15 minutes to cover the same distance What was the average speed during the whole journey?

• 1] 40 mph
• 2] 48 mph
• 3] 50 mph
• 4] 55 mph

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

On a river , Q is the mid - point between two points P and R on the same bank of the river. A boat can go from P to Q and back in 12 hours, and from P to R in 16 hours 40 minutes. How long would it take to go from R to P?

• 1]

  \({ \text{3}}\frac{3}{7}\) hr

• 2]

  5 hr

• 3]

  \({ \text{6}}\frac{2}{3}\) hr

• 4]

  \({ \text{7}}\frac{1}{3}\) hr

A man rows to a place 48 km distant and come back in 14 hours. He finds that he can row 4 km with the stream in the same time as 3 km against the stream. The rate of the stream is:

• 1] 1 km/hr
• 2] 1.5 km/hr
• 3] 2 km/hr
• 4] 2.5 km/hr

A boat can travel with a speed of 13 km/hr in still water. If the speed of the stream is 4 km/hr, find the time taken by the boat to go 68 km downstream.

• 1] 2 hours
• 2] 3 hours
• 3] 4 hours
• 4] 5 hours
• 5] None of these

A motorboat in still water travels at a speed of 36 km/hr. It goes 56 km upstream in 1 hour 45 monutes. The time taken by it to cover the same distance down the stream will be-

• 1] 1 hour 24 minutes
• 2] 2 hour 21 minutes
• 3] 2 hour 25 minutes
• 4] 3 hour

P, Q and R are three towns on a river which flows uniformly. Q is equidistant from P and R. I row from P to Q and back in 10 hours and I can row from P to R in 4 hours. Compare the speed of my boat in still water with that of the river.

• 1] 4 : 3
• 2] 5 : 3
• 3] 6 : 5
• 4] 7 : 3

A man takes 2.2 times as long to row a distance upstream as to row the same distance downstream. If he can row 55 km downstream in 2 hour 30 minutes, what is the speed of the boat in the still water?

• 1] 40 km/h
• 2] 8 km/h
• 3] 16 km/h
• 4] 24 km/h

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 boat travels 24 km upstream in 6 hours and 20 km downstream in 4 hours. Then the speed of boat in still water and the speed of current are respectively.

• 1] 4 kmph and 3 kmph
• 2] 4.5 kmph and 0.5 kmph
• 3] 4 kmph and 2 kmph
• 4] 5 kmph and 2 kmph