1. 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.
A. 2 hours
B. 3 hours
C. 4 hours
D. 5 hours
2) A boat running upstream takes 8 hours 48 minutes to cover a certain distance, while it takes 4 hours to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current respectively?
A. 2 : 1
B. 3 : 2
C. 8 : 3
D. Cannot be determined
E. None of these
3) 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:
A. 4
B. 5
C. 6
D. 10
4) A man can row upstream 10 kmph and downstream 20 kmph. Find the man rate in still water and rate of the stream.
A. 0,5
B. 5,5
C. 15,5
D. 10,5
5) A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:
A. 2 mph
B. 2.5 mph
C. 3 mph
D. 4 mph
6) A man can row at 6 kmph in still water. If the velocity of current is 2 kmph and it takes him 3 hour to row to a place and come back, how far is the place?
A. 9 km
B. 8 km
C. 3 km
D. 12 km
7) A man takes twice as long to row a distance against the stream as to row the same distance in favour of the stream. The ratio of the speed of the boat in still water and stream is
A. 3:1
B. 1:3
C. 2:4
D. 4:2
8) A boat goes downstream 12.8km in 32min . And the river flowing is 1/7th of th boat's speed in still water.. how long the boat will cover in 34min in upstream?
A) 10.2km
B) 12.2km
C) 11.2km
D) 24km
E) none
9)A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?
A. 40minutes
B. 1hour
C. 1 hr 15 min
D.1 hr 30min
10) Boat speed in still water is 9 kmph, current speed 1.5 kmpd have to cover a certain distance of 105 km one side and come back to the starting point. Total time ?
A) 22
B) 24
C) 12
D) 21
E) none
Answers :
1) C
68÷(13+4)=4hour
2) C
Up time : down time
528 : 240=11:5
Up speed: down speed
=5:11
Boat= (11+5)÷2=8
Stream=(11-5)÷2=3
8:3
3) B
(30/15+x) + (30/15-x)=9/2
X=5
4) C
Boat=(20+10)÷2=15
Stream=(20-10)÷2=5
5) A
(36/10-x) - (36/10+x)=3/2
X=2km
6) B
(X/6+2) + (X/6-2)=3
X=8km
7) A
Up speed=x
Down speed=2x
Boat=(2x+x)÷2=1.5x
Stream=(2x-x)÷2=0.5x
Ratio=3:1
8) A
32min=> 12.8km
60min=> 24km downstream
Stream:boat=1:7
7x+x=8x=24 down speed
7x-x=6x=18 up speed
60min=> 18
34min=> 10.2
9) C
Up speed=2kmph
Down speed=6kmph
Boat=(6+2)÷2=4
4km=> 1hour
5km=> 1hour 15min
10) B
Up speed=9-1.5=7.5
Down speed=9+1.5=10.5
(105/7.5)+ (105/10.5)=24
A. 2 hours
B. 3 hours
C. 4 hours
D. 5 hours
2) A boat running upstream takes 8 hours 48 minutes to cover a certain distance, while it takes 4 hours to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current respectively?
A. 2 : 1
B. 3 : 2
C. 8 : 3
D. Cannot be determined
E. None of these
3) 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:
A. 4
B. 5
C. 6
D. 10
4) A man can row upstream 10 kmph and downstream 20 kmph. Find the man rate in still water and rate of the stream.
A. 0,5
B. 5,5
C. 15,5
D. 10,5
5) A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:
A. 2 mph
B. 2.5 mph
C. 3 mph
D. 4 mph
6) A man can row at 6 kmph in still water. If the velocity of current is 2 kmph and it takes him 3 hour to row to a place and come back, how far is the place?
A. 9 km
B. 8 km
C. 3 km
D. 12 km
7) A man takes twice as long to row a distance against the stream as to row the same distance in favour of the stream. The ratio of the speed of the boat in still water and stream is
A. 3:1
B. 1:3
C. 2:4
D. 4:2
8) A boat goes downstream 12.8km in 32min . And the river flowing is 1/7th of th boat's speed in still water.. how long the boat will cover in 34min in upstream?
A) 10.2km
B) 12.2km
C) 11.2km
D) 24km
E) none
9)A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?
A. 40minutes
B. 1hour
C. 1 hr 15 min
D.1 hr 30min
10) Boat speed in still water is 9 kmph, current speed 1.5 kmpd have to cover a certain distance of 105 km one side and come back to the starting point. Total time ?
A) 22
B) 24
C) 12
D) 21
E) none
Answers :
1) C
68÷(13+4)=4hour
2) C
Up time : down time
528 : 240=11:5
Up speed: down speed
=5:11
Boat= (11+5)÷2=8
Stream=(11-5)÷2=3
8:3
3) B
(30/15+x) + (30/15-x)=9/2
X=5
4) C
Boat=(20+10)÷2=15
Stream=(20-10)÷2=5
5) A
(36/10-x) - (36/10+x)=3/2
X=2km
6) B
(X/6+2) + (X/6-2)=3
X=8km
7) A
Up speed=x
Down speed=2x
Boat=(2x+x)÷2=1.5x
Stream=(2x-x)÷2=0.5x
Ratio=3:1
8) A
32min=> 12.8km
60min=> 24km downstream
Stream:boat=1:7
7x+x=8x=24 down speed
7x-x=6x=18 up speed
60min=> 18
34min=> 10.2
9) C
Up speed=2kmph
Down speed=6kmph
Boat=(6+2)÷2=4
4km=> 1hour
5km=> 1hour 15min
10) B
Up speed=9-1.5=7.5
Down speed=9+1.5=10.5
(105/7.5)+ (105/10.5)=24
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