a) 5 km/hr

b) 3 km/hr

c) 6 km/hr

d) 8 km/hr

correct answer is: b) 3 km/hr

**Explanation**

We know,

Speed = \frac{Distance}{Time}

And converting “m/sec” to “km/hr” requires multiplying by \left(\frac{3600}{1000}\right)\ or \ \left(\frac{18}{5}\right) . Here “3600 seconds = 1 hour & 1000 metre = 1 kilometre”.

So, speed = \left(\frac{5}{6}\ \times\ \frac{18}{5}\right) km/hr

\rightarrow\ 3\ km/hr**Ans:** Speed = 3 km/hr.