# A man walks ‘a’ km in ‘b’ hours. The time taken to walk 200 meters is :

A man walks ‘a’ km in ‘b’ hours. The time taken to walk 200 meters is :
[A]$\frac{b}{a}hours$
[B]$\frac{b}{5a}hours$
[C]$\frac{ab}{200}hours$
[D]$\frac{200b}{a}hours$

$\mathbf{\frac{b}{5a}hours}$
Man’s Speed $= \frac{Distance}{Time}$
$= \frac{a}{b}km/hr$
$= \frac{1000a}{b}m/hr$
∴ Time taken in walking 200 metre
$= \frac{200}{\frac{1000a}{b}} = \frac{b}{5a}hours$
Hence option [B] is correct answer.