A man takes 3 hours 45 minutes to row a boat | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) Let the speed of the boat in still water be $x \; km/hr$ and the speed of the river current be $y \; km/hr$.Downstream speed $= x + y$.Time taken

Vedclass · Accepted Answer

$1$

Vedclass · Answer

(A) Let the speed of the boat in still water be $x \; km/hr$ and the speed of the river current be $y \; km/hr$.Downstream speed $= x + y$.Time taken downstream $= 3 \; hours \; 45 \; minutes = 3 + \frac{45}{60} = 3 + \frac{3}{4} = \frac{15}{4} \; hours$.Distance $= 15 \; km$.Using $	ext{Speed} = \frac{	ext{Distance}}{	ext{Time}}$,we get $x + y = \frac{15}{15/4} = 4 \; km/hr \; \dots (i)$.Upstream speed $= x - y$.Time taken upstream $= 2 \; hours \; 30 \; minutes = 2 + \frac{30}{60} = 2.5 = \frac{5}{2} \; hours$.Distance $= 5 \; km$.Using $	ext{Speed} = \frac{	ext{Distance}}{	ext{Time}}$,we get $x - y = \frac{5}{5/2} = 2 \; km/hr \; \dots (ii)$.Subtracting equation $(ii)$ from equation $(i)$:$(x + y) - (x - y) = 4 - 2$$2y = 2$$y = 1 \; km/hr$.Thus,the speed of the river current is $1 \; km/hr$.

$A$ man takes $3$ $hours$ $45$ $minutes$ to row a boat $15 \; km$ downstream of a river and $2$ $hours$ $30$ $minutes$ to cover a distance of $5 \; km$ upstream. Find the speed of the river current in $km/hr$.

Similar Questions

$A$ sailor goes $12$ $km$ downstream in $48$ $min$ and returns in $1$ $h$ $20$ $min.$ The speed of the sailor in still water is..........$km/h$.

$A$ man can row upstream $36 \text{ km}$ in $6 \text{ hours}$. If the speed of a man in still water is $8 \text{ km/hr}$,find how much distance he can cover downstream in $10 \text{ hours}$? (in $\text{km}$)

$A$ person can swim in still water at $4 \, km/h$. If the speed of the water current is $2 \, km/h$,how many hours will the man take to swim back against the current for $6 \, km$?

$A$ man can row $30 \text{ km}$ upstream and $44 \text{ km}$ downstream in $10 \text{ hours}$. Also,he can row $40 \text{ km}$ upstream and $55 \text{ km}$ downstream in $13 \text{ hours}$. Find the rate of the current and the speed of the man in still water.

$A$ boat goes $40\, km$ upstream in $8\, h$ and $36\, km$ downstream in $6\, h$. The speed of the boat in still water is......$km/h$

Vedclass Test Series

Exam Paper Generator

Online Exam Module