Know the distance ratio and time ratio of a and B objects, how to find their speed ratio

Know the distance ratio and time ratio of a and B objects, how to find their speed ratio

Speed = distance △ time
I.e. v = L / T
The speed, distance and time of a and B are V1, V2, L1, L2, T1 and T2
Then V1 = L1 / T1; V2 = L2 / T2
So V1 / V2 = (L1 / T1) / (L2 / T2)
=(L1/L2)/(T1/T2)
L1 / L2; T1 / T2 is known, V1 / V2 can be obtained