To find out how many seconds separated the top two runners, you subtract the time of the silver medalist (Marileidy Paulino) from the time of the gold medalist (Shaunae Miller-Uibo).
Shaunae Miller-Uibo's time: 48.36 seconds
Marileidy Paulino's time: 49.2 seconds
Now, perform the subtraction:
49.2 - 48.36 = 0.84 seconds
Therefore, the time that separated the top two runners is 0.84 seconds.