Acyclist travels 3km in 10min what's his speed in km/h

   18 kilometers per hour

Step-by-step explanation:

speed = distance /time

     distance given is 3 kilometers  

      time given is 10 minutes  

the answer is supposed to be given in hours so you convert the 10 minutes to hours .hence ;  

                       if 60 minutes = 1 hour  

                  what about 10 minutes= ??

                     10 minutes  *  1 hour /60 minutes  

                  answer is 1/6 hours

so speed = 3 kilometers/1/6 hours  

               =18 kilometers per hour

the two may have that, even a breakdown is probably offered