# Aptitude - Boats & Streams Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to **Boats & Streams**. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using **Show Answer** button. You can use **Next Quiz** button to check new set of questions in the quiz.

Q 1 - A man can push 6 km/hr in still water. It takes him twice as long to line up as to column down the river. Find the rate of the stream.

### Answer : C

### Explanation

Let men's rate upstream be x km/hr`At that point, men's rate downstream = 1/2 (2x+x) km/hr = 3x/2 km/hr`And there 4; 3x/2 =6 <=> x= (2*6)/3 =4.`And there 4: 4 km/hr, rate downstream = (2*4) km/hr = 8 km/hr`Rate of stream = 1/2 (8-4) km/hr = 2 km/hr

Q 2 - A man can push 8km/hr in still water. At the point when the waterway is running at 2km/hr it takes him 3hrs 12min to line to a spot and backs. How far is the spot?

### Answer : D

### Explanation

Speed downstream (8+2) km/hr=10km/hr.`Speed upstream= (8-2) km/hr=6km/hr.`Let the required separation be x km. at that point,`X/10+x/6+16/5=>3x+5x=96=>8x=96=>x=12.`Required separation =12 km.

Q 3 - A boat is paddled downstream at 15.5km/hr and upstream at 8.5km/hr. The rate of the stream is:

### Answer : A

### Explanation

Speed downstream =15.5km/hr, Speed upstream =8.5km/hr.`Speed of the stream=1/2(15.5-8.5) km/hr=3.5 km/hr

Q 4 - A steamer goes downstream starting with one port then onto the next in 4 hours. It covers the same separation upstream in 5 hours. In the event that the velocity of the stream is 2km/hr, the separation between the two ports is:

### Answer : D

### Explanation

Let the distance between the two ports be x km. Then,`Speed downstream =x/4 km/hr, Speed upstream=x/5 km/hr.`Speed of the stream=1/2(x/4-x/5).`∴ 1/2 (x/4- x/5) = 2 => x/4 -x /5 = 4 => x = 80.`Hence, the distance between the two ports is 80 km.

Q 5 - The velocity of a speedboat is that of the flow of water as 36:5. The vessel obliges the current in 5 hours 10min. It will return:

### Answer : C

### Explanation

Let the speed of motorboat be 36x km/hr and that of the current of water be 5x km/hr.`Speed downstream = (36x+ 5x) km/hr=41x km/hr,`Speed upstream = (36x-5x) km/hr=31x km/hr.`Distance covers downstream = (41x*31/6) km.`Distance upstream= [(41*31) x/6 * 1/31x] hrs = 41/6 hrs = 6 hrs 50 min.

Q 6 - In a waterway, a man takes 3 hours in paddling 3 km upstream or 15km downstream. What is the rate of the current?

### Answer : A

### Explanation

Speed upstream =3/3 km/hr =1 km/hr.`Speed downstream =15/3 km/hr=5 km/hr.`Speed of current =1/2 (5-1) km/hr =2 km/hr

Q 7 - A vessel goes 6 km in an hour in still water. It requires thrice as much investment in covering the same separation against the current. Velocity of the current is:

### Answer : C

### Explanation

Speed in still water =6 km/hr.`Speed against the current =6/3 km/hr =2 km/hr`Let the speed of the current be x km/hr`6-x = 2 => x = 4 km/hr.

Q 8 - A motor boat in still water travels at a speed of 36 kmph. It goes 36 km upstream in 1 hr 45 mins. The time taken by it to cover the same distance downstream will be

### Answer : C

### Explanation

Upstream Speed of motor boat = 56/1 hr 45 min = 32 kmph`Speed of the motor boat in still water = 36 kmph`Speed of the boat in still water = 1/2*(Downstream Speed + Upstream Speed)`36 = 1/2(d + 32)`Downstream Speed (d) = 40 km/hr``t = Distance/speed = 40/36 = 7/5 hr = 1 hr 24 mins

Q 9 - A boatman goes 2km against the current of stream in 40 min. what's more, comes back to the same spot in 30 min. What is his rate of paddling in still water?

### Answer : C

### Explanation

Distance covered upstream in 40min = 4 km.`Distance covered upstream in 60 min = (4/40*60) km= 6 km`Distance covered downstream a in 30 min = 4 km`Distance covered downstream in 60 min = (4/30 * 60) km = 8 km.`Speed upstream =3 km/hr, speed downstream =4 km/hr.`Speed in still water = 1/2 (6 +8) km/hr=7 km /hr.

Q 10 - The current of a stream keeps running at 4km 60 minutes. A boat goes 6 km and back to the beginning stage in 2hour. The rate of the boat in still water is:

### Answer : C

### Explanation

Let the speed in still water be x km/hr. Then,`Speed downstream = (x+ 4) km/hr, speed upstream = (x-4) km/hr.`6/(x+4) + 6 /(x-4) = 2 => 1/(x+4) +1/(x-4)=2/6 =1/3 =>(x+4)+(x-4)/x^{2}-16=1/3 =>x^{2}-16=6x`=> x^{2}-6x-16=0=> (x-8) (x+2) = 0 => x = 8.∴ Speed of boat in still water = 8 km/hr.