The current of a stream runs at the rate of 4 km an hour. A boat goes 6 km and comes back to the starting point in 2 hours. The speed of the boat in still water is
1). 6 km/hour
2). 8 km/hour
3). 7.5 km/hour
4). 6.8 km/hour
A sailor goes 12 km downstream in 48 minutes and returns in 1 hour 20 minutes. The speed of the sailor in still water is :
1). 12 km/hr
2). 12.5 km/hr
3). 13 km/hr
4). 15 km/hr
A man can row 15km/hr downstream and 9 km/hr upstream. The speed of the boat in still water is
1). 8 km/hr.
2). 10 km/hr.
3). 15 km/hr.
4). 12 km/hr.
The speed of the current is 5 km/hour. A motorboat goes 10 km upstream and back again to the starting point in 50 minutes. The speed (in km/hour) of the motorboat in still water is
1). 20
2). 26
3). 25
4). 28
A boat goes 12 km downstream and comes back to the starting point in 3 hours. If the speed of the current is 3 km/ hr, then the speed (in km/ hr) of the boat in still water is
1). 12
2). 9
3). 8
4). 6