Question

A person crosses a 174m long bridge in 45 seconds. what is his speed in km/h?

Answer 1

`13.92km`/hr

Explanation:

1000m=1km SO 174m=`174/1000=0.174`km

Since the person travels 0.174km per 45 seconds, then in 60 seconds or 1 minute they travel:`0.174times60/45=29/125=0.232km`

So in 1 minute, they travel 0.232km. Since there is 60 minutes in one hour, we do: `0.232times60=13.92km`

Therefore, their speed in km/hr is `13.92km`/hr