# 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 upstream at 6km/hr and downstream at 10 km/hr. Discover man's rate in still water and the rate of the momentum.

### Answer : C

### Explanation

Speed upstream =6 km/hr`Speed downstream = 10 km/hr`Rate in still water = 1/2 (10-6) km/hr. = 6km/hr`Rate of the current = 1/2 (10+6) km/hr =8 km/hr

Q 2 - A man can push 30km upstream and 44km downstream in 10 hours. Additionally, he can push 40km upstream and 55km downstream in 13 hours. Discover the rate of flow and the current of the man in still water.

### Answer : C

### Explanation

Let speed upstream be x km/hr and the velocity downstream be y km/hr`At that point, 30/x+44/y=10 ... (i) and 40/x+55/y=13 ... (ii)`Increasing (ii) by 4, (i) by 5 and subtracting, we get: 10/x=2=>x=5.`Putting x=5in (i) we get 4y=44=> y=11.`∴ Speed upstream =5km/hr, speed downstream=11km/hr.`Velocity of the current =1/2(11-5) km/hr=3km/hr.`Velocity of man in still water =1/2(11+5) km/hr=8km.

Q 3 - A boat goes 24km downstream in 10 hours. It takes 2 hours more to cover the same separation against the stream. What is the rate of the watercraft in still water?

### Answer : A

### Explanation

Speed downstream =24/10 km/hr=2.4 km/hr`Speed upstream =24/12 km/hr =2 km/hr`Speed of the boat in still water=1/2(2.4+2) km/hr=2.2 km/hr.

Q 4 - A watercraft covers a separation of 30km in 5/2 hrs running downstream. While returning, it covers the same separation 15/4hrs .What is the velocity of the watercraft in still water?

### Answer : D

### Explanation

Speed downstream = (30*2/5) km/hr=12km/hr.`Speed upstream= (30*4/15) km/hr=8 km/hr.`Speed of boat in still water=1/2(12+8) km/hr=10 km/hr.

Q 5 - A boat can push 1 km with stream in 10 minutes and 1 km against stream in 20 minutes. What is the rate of the vessel in still Water?

### Answer : D

### Explanation

Distance moved downstream in 10 min=1km.`Distance moved downstream in 60 min= (1/10*60) km=6 km.`Distance moved upstream in 20 min =1 km.`Distance moved upstream in 60 min = (1/20*60) km = 3 km.`Speed downstream =6 km/hr, Speed upstream =3 km/hr`Speed of the boat in still water =1/2(6+3) km/hr =4.5 km/hr.

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 - 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.

Q 10 - Aman lines to a spot 48 km far off and in 14 hours. He finds that he can push 4km with the stream in the same time as 3km against the stream. The rate of the stream is:

### Answer : B

### Explanation

Suppose he moves 4 km downstream in x hrs.`Then, speed downstream = 4/x km/hr, speed upstream =3/x km/hr`∴ 48/ (4/x) + 48 / (3/x) = 14 => 12x + 16x =14 => 28x = 14`=> x= 1/2.`Speed downstream = 4 / (1/2) km/hr=8 km/hr.`Speed upstream= 3/(1/2) km/hr =6km/hr.`Rate of stream = 1/2(8 - 6) km /hr=1 km/hr.