So if he run 99yd in 10 seconds, we convert yards into meters.
Since [tex]1yd = 0.9144m[/tex], then [tex]99yd = 90.5256m[/tex].
Then we do: [tex]90.5256m[/tex] ÷ [tex]10s[/tex] = 9.05256m/s.
Then we divide [tex]458m [/tex] ÷ [tex]9.05256m[/tex] = 50.5934233s
So the answer is: He ran 458m in 50.5934233s.
Hope this helped! c: