Question

A man can row against the current three fourth of a kilometer in 15 min and returns same distance in 10 min, then ratio of his speed to that of current?
A) 5:1
B) 3:1
C) 4:1
D) 2:1

Answer 1

Description for Correct answer:
Let the speed of man and current be x and y km/h, respectively. 

Speed upstream = (x - y) km/h 

Speed down stream = (x +y) km/h 

According to the question, 

3×604×15=x−y3×604×15=x−y

= x - y = 3 ...(i)

and 34×6010=x+y34×6010=x+y

= x + y = 9292 ...(ii)

On adding Eqs. (i) and (ii), we get

2x=3+922x=3+92

2x=6+922x=6+92

x=154x=154

On putting the value of x in Eq. (ii), we get

154+y=92154+y=92

y=92−154=18−154y=92−154=18−154

= y=34y=34

Hence, speed of man x=154x=154 and

Speed of current y=34y=34

Hene, required ratio = 154:34=5:1

Answer 2

$\huge{\boxed{\red {\bf{Answer}}}}$


$<b>$
A man can row against the current three fourth of a kilometer in 15 min and returns same distance in 10 min, then ratio of his speed to that of current?
A) 5:1
B) 3:1
C) 4:1
D) 2:1

$\huge\underline{\green {\textbf{A) 5:1}}}$

$<font color = purple>$

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