A. 10 kmph
B. 21 kmph
C. 8 kmph
D. 12 kmph
Explanation:
S = 4
M = x
DS = x + 4
US = x – 4
6/(x + 4) + 6/(x – 4) = 2
x = 8
Related Mcqs:
- The speed of a boat in upstream is 60 kmph and the speed of the boat downstream is 80 kmph. Find the speed of the boat in still water and the speed of the stream?
A. 70, 10 kmph
B. 35, 27 kmph
C. 50, 60 kmph
D. 45, 55 kmph - The current of a stream at 1 kmph. A motor boat goes 35 km upstream and back to the starting point in 12 hours. The speed of the motor boat in still water is_________?
A. 6 kmph
B. 7 kmph
C. 8.5 kmph
D. 8 kmph - Speed of a boat in standing water is 9 kmph and the speed of the stream is 1.5 kmph. A man rows to a place at a distance of 105 km and comes back to the starting point. The total time taken by him is_________?
A. 16 hours
B. 18 hours
C. 20 hours
D. 24 hours - A boat goes 24 km downstream in 10 hours, it takes 2 hours more to cover the same distance against the stream. What is the speed of the boat in still water?
A. 2km/hr
B. 2.8 km/hr
C. 4 km/hr
D. 4.2 km/hr
E. None of these - The time taken by a man to row his boat upstream is twice the time taken by him to row the same distance downstream. If the speed of the boat in still water is 42 kmph, find the speed of the stream?
A. 12 kmph
B. 13 kmph
C. 14 kmph
D. 15 kmph - The speed of a motor boat is that of the current of water as 36:5. The boat goes along with the current in 5 hours 10 min, it will come back in_______?
A. 5 hours 50 min
B. 6 hours
C. 6 hours 50 min
D. 12 hours 10 min - A boat running upstream takes 8 hours 48 min 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 the speed of water current respectively?
A. 2 : 1
B. 3 : 1
C. 8 : 3
D. Cannot be determined - The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 60 metres?
A. 10 seconds
B. 15 seconds
C. 20 seconds
D. 12 seconds
E. None of these - A man can row a boat at 20 kmph in still water. If the speed of the stream is 6 kmph, what is the time taken to row a distance of 60 km downstream?
A. 20/6 hours
B. 27/2 hours
C. 30 hours
D. 30/13 hours - A car gives a mileage of 20 km per liter of petrol when driven at a constant speed of 50 kmph but the mileage decreases by 10% when driven at a speed of 70 kmph. How many km can the car travel with 12 liters of petrol if it travels a speed of 70 kmph?
A. 216 km
B. 240 km
C. 228 km
D. 200 km
