A man can row 15 km per hour downstream and 9 km per hour upstream. The speed (in kmph) of the boat in still water is
10
12
15
15
A boat covers 12 km upstream and 18 km downstream in 3 hours, while it covers 36 km upstream and 24 km downstream in
What is the speed of the current?
1.5 km/hr
1 km/hr
2 km/hr
2.5 km/hr
A man can row against the current three-fourth of a kilometre in 15 minutes and returns the same distance in 10 minutes. The ratio of his speed to that of the current is
3 : 5
5 : 3
1 : 5
1 : 5
A boat moves downstream at the rate of 1 km in minutes and upstream at the rate of 5 km an hour. what is the speed of the boat in the still water?
4 km/hour
4 km/hour
If the speed of a boat in still water is 20 km/hr and the speed of the current is 5 km/hr, then the time taken by the boat to travel 100 km with the current is
2 hours
3 hours
4 hours
4 hours
C.
4 hours
Distance = 100 km
Speed of boat in still water = 20 km/hr
Speed of current = 5 km/hr
Relative speed = (20 + 5)km/hr = 25 km/hr
Required Time
A boat moves downstream at the rate of 8 km/hr and upstream at 4 km/hr. The speed of the boat in still water is:
4.5 km/hr
5 km/hr
6 km/hr
6.4 km/hr
Speed of a boat along and against the current are 14 km/hr and 8 km/hr respectively. The speed of the current is
11 km/hr
6 km/hr
5.5 km/hr
3 km/hr
A man can row 6 km/h in still water. If the speed of the current is 2 km/h, it takes 3 h more in upstream than in the downstream for the same distance. The distance is
30 km
24 km
20 km
32 km
A ship is moving at a speed of 30 km/h. To know the depth of the ocean beneath it. It sends a radio wave which travels at a speed 200 m/s. The ship receives the signal after it has moved 500 m. The depth of the ocean is
√143/2 km
12 km
6 km
8 km
A swimmer swims from a point A against a current for 5 min and then swims backwards in favour of the current for next 5 min and comes to the point B. If AB = 100 m, then the speed of the current in (km/h) is
1
0.6
0.4
0.2