Transmission time of 1 frame = $2 * T_p = \large \frac{\text{Frame size}}{ \text{Data rate}}$
Let Frame size be $x$,
Transmission time of 1 frame = $2 * \frac{D}{\text{Speed of Propagation}} = \large \frac{x}{\text{Data rate}}$
where D = Distance between source and destination.
$D = \Large \frac{ \text{ Speed of Propagation } * \ x }{2 \ * \ \text{Data rate}} $
$ \text{ Speed of Propagation and Frame size are constant.} $
Hence we know that Distance and Data Rate are inversely proportional.
$10 Mbps \rightarrow 2500m$
$100 Mbps \rightarrow 250m$
$1 Gbps \rightarrow 25m$
$10 Gbps \rightarrow 2.5m$