Question

A column of men, expending $250m$ in length takes one hour to march through street at the rate of $50$ paces a minute, each pace being $75cm$. Find the length of the street

• A. $2000m$
• B. $1500m$
• C. $1000m$
• D. $1750m$

Answer 1

The correct option is A $2000m$

The column of men march. at the rate of 50 paces a minute and each pace is of 75 cm.

$\therefore 75cm=\frac{75}{100}m$

and 50 paces / minute $=\frac{50}{60}$ paces / second

$\therefore$ Their speed $=\frac{75\times 50}{100\times 60}=\frac{5}{8}m/sec$

$\therefore$ In one hour they march $(\frac{5}{8}\times 3600)m$

[ Distance = speed X time ]

[ And here 1 hour = 3600 second ]

$\therefore$ They cover 2250 m in one hour.

Since the column expanded 250 m in length.

$\therefore$ The length of the street $=(2250-250)m=2000m$

$\therefore$ option A is correct.