Given parameters:
Speed of Cyclist 1 Â = 7mph
Speed of Cyclist 2 = 11mph
Time of travel  = 30min  = 0.5hr(60min  = 1hr)
Unknown:
Distance separating them  = ?
To solve this problem, we must understand that speed is the distance per unit time traveled.
Mathematically;
      Speed  = [tex]\frac{Distance}{Time}[/tex]
Now we are to find the distance separating the two cyclists;
      Distance  = speed x time
To find the distance separating the two cyclists, find the sum of their individual distances covered.
 Distance separating them = Distance covered by cyclist 1  + Distance covered by cyclist 2
Now input the parameters;
   Â
Distance of separation = Â (7 x 0.5) Â + Â (11 x 0.5) Â = 3.5 + 5.5 = 9miles
The distance separating them is 9miles