Boats and Streams
1. A boat's speed in still water is 12 km/h. The stream flows at 3 km/h. What is its downstream speed?
A. 9 km/h
B. 15 km/h
C. 12 km/h
D. 18 km/h
B. 15 km/h
2. A boat's speed in still water is 15 km/h. Against a current of 4 km/h, its upstream speed is:
A. 11 km/h
B. 15 km/h
C. 19 km/h
D. 20 km/h
A. 11 km/h
3. A boat travels 20 km downstream in 2 hours and 16 km upstream in 4 hours. What is its speed in still water?
A. 6 km/h
B. 7 km/h
C. 8 km/h
D. 9 km/h
B. 7 km/h
4. A boat's downstream speed is 18 km/h and upstream speed is 12 km/h. The stream's speed is:
A. 2 km/h
B. 3 km/h
C. 4 km/h
D. 6 km/h
B. 3 km/h
5. A boat travels 30 km downstream at 10 km/h. How long does it take?
A. 2 hours
B. 3 hours
C. 4 hours
D. 5 hours
B. 3 hours
6. A boat travels upstream at 5 km/h for 6 hours. How far does it go?
A. 20 km
B. 30 km
C. 40 km
D. 50 km
B. 30 km
7. Two boats have still-water speeds of 8 km/h and 12 km/h. If the stream flows at 2 km/h, what is their downstream speed difference?
A. 2 km/h
B. 4 km/h
C. 6 km/h
D. 8 km/h
B. 4 km/h
8. A boat travels 24 km downstream and returns in 6 hours. If downstream speed is 12 km/h and upstream speed is 8 km/h, what is the stream speed?
A. 1 km/h
B. 2 km/h
C. 3 km/h
D. 4 km/h
B. 2 km/h
9. A motorboat (speed=15 km/h in still water) overtakes a raft (floating with the stream) in 2 hours. If the stream flows at 3 km/h, how far apart were they initially?
A. 24 km
B. 36 km
C. 30 km
D. 40 km
C. 30 km
10. A boat's upstream speed is half its downstream speed. What is the ratio of boat speed to stream speed?
A. 1:2
B. 2:1
C. 3:1
D. 4:1
C. 3:1
11. A boat takes twice as long to travel upstream as downstream for the same distance. If stream speed is 3 km/h, what is the boat's still-water speed?
A. 6 km/h
B. 9 km/h
C. 12 km/h
D. 15 km/h
B. 9 km/h
12. A boat travels 40 km upstream in 5 hours. If the stream speed is 2 km/h, how far can it travel downstream in 4 hours?
A. 48 km
B. 56 km
C. 64 km
D. 72 km
B. 56 km
13. A boat takes 3 hours downstream and 5 hours upstream for 60 km. The stream speed is:
A. 2 km/h
B. 4 km/h
C. 6 km/h
D. 8 km/h
B. 4 km/h
14. A boat travels 24 km upstream and returns in 6 hours. If the stream flows at 2 km/h, what is the boat's still-water speed?
A. 6 km/h
B. 8 km/h
C. 10 km/h
D. 12 km/h
B. 8 km/h
15. Two boats race 30 km downstream. Boat A's still-water speed is 10 km/h, Boat B's is 15 km/h. If the stream flows at 5 km/h, who wins and by how much time?
A. A by 1 hour
B. B by 0.5 hour
C. A by 0.5 hour
D. B by 2 hours
B. B by 0.5 hour
16. A raft floats downstream from point A to B in 6 hours. A motorboat (speed=12 km/h in still water) takes 2 hours to return from B to A. What is the stream speed?
A. 2 km/h
B. 3 km/h
C. 4 km/h
D. 6 km/h
B. 3 km/h
17. A boat's downstream speed is 2.5 times its upstream speed. What is the ratio of boat speed to stream speed?
A. 2:1
B. 7:3
C. 5:2
D. 3:1
B. 7:3
18. A boat travels 45 km downstream in 3 hours and 30 km upstream in 5 hours. What is its still-water speed?
A. 10.5 km/h
B. 12.5 km/h
C. 15 km/h
D. 18 km/h
A. 10.5 km/h
19. A motorboat (speed=20 km/h in still water) overtakes another boat (speed=15 km/h in still water) moving downstream. If the stream flows at 5 km/h, how much distance will be between them after 2 hours?
A. 10 km
B. 20 km
C. 30 km
D. 40 km
A. 10 km
20. A boat travels 60 km downstream and returns in 9 hours. If downstream speed is 15 km/h, what is the upstream speed?
A. 5 km/h
B. 10 km/h
C. 12 km/h
D. 13 km/h
C. 12 km/h