Answer
$RN$ occurs before $FF$
Work Step by Step
We can find $\gamma$:
$\gamma = \frac{1}{\sqrt{1-\beta^2}}$
$\gamma = \frac{1}{\sqrt{1-0.900^2}}$
$\gamma = 2.294$
We can find the length of the train in the tunnel view:
$L = \frac{L_0}{\gamma}$
$L = \frac{200~m}{2.294}$
$L = 87.2~m$
In the tunnel view, the length of the tunnel is $200~m$
When the rear of the train reaches the near end of the tunnel (RN), the front of the train has not yet reached the far end of the tunnel (FF).
Therefore, $RN$ occurs before $FF$
