Question 286464
Let Vb=velocity of the bike=21km/h
    Vm=velocity of the motorcycle = 63km/h

The distances they travel are equal, because it's the same route and they left from the same place. We know the equation D=VT, where D=distance, V=velocity and T=time. Because the distances for the motorcycle and bike are the same, we can just set them equal to each other:

D=D
Vb*Tb = Vm*Tm

The time the motorcycle travels is 2 hours less than the time the bike travels, so Tm=Tb-2

Vb*Tb = Vm(Tm-2)
21Tb = 63(Tb-2)
126 = 42Tb
Tb=3

The bike travels for 3 hours. The motorcycle travels for 2 hours less, so 1 hour. They meet at 1:00pm.