Question

A man rows upstream 13kms and downstream 28 kms taking 5hours each time. The velocity of the current is?

Answer 1

so tough.............

Answer 2

$\large\underline\pink{Given:-}$

• A man rows upstream 13kms and downstream 28 kms taking 5hours each time.

$\large\underline\pink{To find:-}$

• Fine The velocity of the current is ....?

$\large\underline\pink{Solutions:-}$

• Let the speed of boat be x km/hr and speed of current be y km/hr.

Speed of boat in upstream = (x - y) km/hr

speed = distance/time

x - y = 13/5

5x - 5y = 13 _________(i).

Speed of boat in upstream = (x + y) km/hr

speed = distance/time

x + y = 28/5

5x + 5y = 28 _________(ii).

Now, Solving the Eq. (ii) and (i). we get,

${5x} \: + \: {5y} \: \: = \: \: {28} \\ {5x} \: - \: {5y} \: \: = \: \: {13} \\ \underline{ - \: \: \: \: \: \: \: \: \: \: \: + \: \: = \: \: \: - \: \: \: \: \: \: \: \: } \\ \: \: \: \: \: \: \: \: \: {10y} \: \: \: \: \: = \: \: \: {15}$

$\: \: \: \: \: \leadsto \: \: y \: \: = \: \: \frac{15}{10}$

$\: \: \: \: \: \leadsto \: \: y \: \: = \: \: {1.5} \: km/hr$

Hence, The velocity of the current is 1.5 km/hr.