A person crosses a 700 m long bridge in 31/2 minutes. The speed of th…

Distance covered in $3\frac{1}{2}$ minutes = 700 meters

Distance covered in 1 minute = 700 × $\frac{2}{7}$ = 200 meters

So, the distance covered in 60 minutes = 200 × 60 × \(\frac{1}{1000}\) = 12 kilometers.