# 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 columns 30 km downstream and 18 km upstream, taking 5 hours every time. Every time what is the speed of the current?

A - 1.2 km/hr

B - 1 km/hr

C - 2 km/hr

D - 1.5 km/hr

### Explanation

`Speed downstream = 30/5 km/hr = 6km/hr`Speed upstream = 18/5 km/hr = 3.6 km/hr`Speed of the current = 1/2 (6-3.6) km/hr = 2.4/2 km/hr = 1.2 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.

A - 4,5 km/hr

B - 5,6 km/hr

C - 3,8 km/hr

D - 7,9 km/hr

### 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 running downstream covers 24kms in 4 hours, while for covering the same separation upstream it takes 6 hours. What is the velocity of the watercraft in still water?

A - 3.5 km/hr

B - 5 km/hr

C - 6.5 km/hr

D - 7 km/hr.

### Explanation

`Speed downstream =24/4km/hr=6 km/hr.`Speed upstream =24/6 km/hr=6 km/hr.`Speed of the boat in still water=1/2(6+4) km/hr=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:

A - 50 km

B - 60 km

C - 70 km

D - 80 km

### 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 pace of a watercraft in still water is 15km/hr. It can go 30 km upstream and return downstream to the first point in 4hrs 30min. The velocity of the stream is:

A - 5 km/hr

B - 8 km/hr

C - 10 km/hr

D - 15 km/hr.

### Explanation

`Let the speed of the stream be x km/hr.`Speed downstream= (15+x) km/hr, Speed upstream= (15-x) km/hr`30/ (15+x) + 30/ (15-x) = 54/60 => 30/ (15+x) + 30/ (15-x) =9/2.`=> 1/ (15+x) + 1/ (15-x) = 9/2*30= 3/20`=> (15-x) + (15+x) / (15+x) (15-x) = 3/20.`=> 3 (225-x2) = 600 => 3x2 = 75`=> x2 = 25 => x=5.`Speed of stream = 5 km/hr.`

Q 6 - Aman can push at 5 km/hr in still Water. It the stream is running at 1km/hr, it takes him 75 min. to line to a spot and back. How far is the spot?

A - 2.5 km

B - 3 km

C - 4 km

D - 5 km

### Explanation

`Speed downstream = (5+1) km/hr=6 km/hr`Speed upstream = (5-1) km/hr=4 km/hr.`Let the required distance be x km. Then,`x/6+ x/4=75/60 = 5/4 => (2x+3x) =15 => 5x = 15 => x=3.`Required distance =3km.`

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:

A - 16 km/hr

B - 18 km/hr

C - 24 km/hr

D - 28 km/hr.

### Explanation

`Let the speed of the steamer in still water be x km/hr.`Speed downstream = (x +2) km/hr, speed upstream = (x-2) km/hr.`Then 4 (x+2) = 5 (x-2) => x = 18.`Hence, the speed of the streamer in still water is 18 km/hr.`

Q 8 - A man can push seventy five percent of a kilometer against the stream in 45/4min. what's more, return in 15/2min. The velocity of the man in still water is:

A - 2 km/hr

B - 3 km/hr

C - 4 km/hr

D - 5 km/hr

### Explanation

`Distance covered upstream in 45/4 min =3/4 km.`Distance covered upstream in 1 hr = (3/4*4/45*60) km/hr = 4 km /hr.`Distance covered upstream in 15/2 min = 3/4 km.`Distance covered upstream in 1 hr = (3/4*2/15*60) km/hr = 6 km/hr`Speed of the man in still water = 1/2 (6 +4) km/hr = 5 km/hr`

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?

A - 5 km/hr

B - 6 km/hr

C - 7 km/hr

D - 8 km/hr

### 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 - 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:

A - 0.5 km/hr

B - 1 km/hr

C - 3.5 km/hr

D - 1.8 km/hr

`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.`