Bissoy.com
Doctors Medicines MCQs Q&A

A man can row upstream at 12km/hr and downstream at 18 km/hr. The man rowing speed in still water is?

A man can row upstream at 12km/hr and downstream at 18 km/hr. The man rowing speed in still water is? Correct Answer 15 km/hr

Speed of boat in still water = $$\frac{{x + y}}{2}$$
Where (x = downstream speed) and (y = upstream speed)
∴ Boat's speed
$$\eqalign{ & {\text{ = }}\frac{{18 + 12}}{2} \cr & = \frac{{30}}{2} \cr & = 15\,km/hr \cr} $$

Related Questions

What is the distance covered by boat N upstream in 5 hours? Which of the following option is sufficient alone to find the answer? A) Boat M is travelling downstream with 20% more downstream speed of boat N. Speed of boat M in still water is 10% more than the speed of boat N in still water. B) Boat M and Boat N are travelling downstream with speed 33 km/hr and 40 km/hr respectively and speed of boat M is still water is 2 times the speed of stream. C) Speed of boat M in still water is 6 km/hr less then speed of boat N in still water and speed of stream is 10 km/hr. D) Speed of stream is ½ times the speed of boat N in still water and downstream speed of boat M is 44 km/hr. E) Speed of stream is 10 km/hr and ratio of upstream speed of boat M and boat N is 3 : 2 respectively.
Given below are two quantities named A & B. Based on the given information, you have to determine the relation between the two quantities. You should use the given data and your knowledge of Mathematics to choose between the possible answers Quantity A: A man can row at 28/3 km/hr speed in still water and he finds that it takes him thrice as much time to row upstream as to row downstream. Find the speed of current. Quantity B: The speed of a boat in still water is 10 km/hr. If it can travel 26 km downstream and 14 km upstream in the same time, what is the speed of the stream?
Given below are three quantities named 1, 2 and 3. Based on the given information, you have to determine the relation between the three quantities. You should use the given data and knowledge of Mathematics to choose between the possible answer. Quantity 1: Manish can row at a speed of 4.5 km/h in still water and rows to a certain upstream point and back to the starting point in a river which flows at 1.5 km/hr. Find his average speed for total journey. Quantity 2: A man can row 6 km/h in still water. It takes him twice as long to row up as to row down the river. Find the rate of stream. Quantity 3: The rate of flow of river water is 4 km/h. A boat goes up 6 km and back to the starting point in 2 hour. Find the speed of the boat in still water.
In the following question, two statements are numbered as A and B. On solving these statements we get quantities A and B respectively. Solve for both quantities and chose the correct option. Quantity A: A man takes 11/9 times downstream time to row upstream keeping the distance same in both cases. What is the speed of boat (m/s) in still water if it takes 6 hours to travel 80 km in downstream? Quantity B: A boat running in upstream covers 20 km distance in 3 hours while covering the same distance in downstream it takes 2 hours. What is the speed of the boat in still water (m/s)?
Questions below followed by two quantities. Find the relation between them. The table shows the distance travelled by five different boats upstream, the speed of the boat in still water and the time taken by them to cover the upstream distance. Boats Upstream distance Speed of boat Time taken  A  240 km  15 km/hr  20 hr  B  150 km  10 km/hr  25 hr  C  350 km  20 km/hr  50 hr  D  96 km  8 km/hr  16 hr  E  126 km  26 km/hr  9 hr   Quantity I: Boat B travel 238 km distance downstream in certain time. How much downstream distance boat D will cover at the same time? Quantity II: Boat E travel 722 km distance downstream in certain time. How much downstream distance boat A will cover at the same time?
In the following question, two statements are numbered as A and B. On solving these statements we get quantities A and B respectively. Solve for the both quantities and chose the correct option. Quantity A: The ratio of speed of boat to speed of stream is 2 : 1, If the boat travels 162 km and come back to starting point in 36 hour. What is the difference between the time taken by the boat to go upstream and the time taken by the boat to go downstream? Quantity B: The speed of the stream is 6 km/hr and the distance travelled by the boat is 60 km. If the boat covered half distance upstream with usual speed and other half with double its speed, then it takes 7.5 hours less time than usual time to go upstream. Find the total time taken by the boat to go upstream and downstream?
A man can row 30 km upstream and 44 km downstream in 10 hours, whereas he can row 40 km upstream and 55 km downstream in 13 hours. Find the rate of the current and the speed of the man in still water respectively.
Study the following questions carefully and answer accordingly. Quantity - I) If the time taken by a boat to cover the same distance in upstream is 2 hours more than downstream. The downstream speed of the boat and the speed of current is 16 kmph and 4 kmph then find the total distance travelled by the boat? Quantity - II) If the time taken by the boat in upstream and in downstream is 16 hours and 10 hours to cover the same distance. Then find the speed of boat in still water is how much percent of the speed of stream? Quantity – III) If the length of rectangle is twice of its breadth and 3 times more than the side of square and the difference between the side of square and length of rectangle is 15 cm then find the area of rectangle ?
If the sum of the total time taken by boats X1 to travel D km each upstream and X2 to travel downstream is 4 hours and the sum of the total time taken by boats X1 to travel downstream and X2 to travel upstream the same distance D km each is 12 hours. Time taken by X2 to travel upstream exceeds its downstream time by t1 hours. Similarly, the time taken by X1 to travel upstream exceeds its downstream time by t2 hours. What is the value of (t1 - t2)?
A craft takes twice time in rowing a certain distance upstream than downstream. What is the ratio between the craft's speed of rowing in still water and speed of stream?