Answer :
[tex]75\ meters\ in\ 30\ second\\\\
x\ meters\ in\ 1\ second\\\\
Proportion:\\
75-30\\x-1\\\\cross\ multiplication\\\\
75=30x\ \ \ \ | divide\ by\ 30\\\\
x=2,5meters\\\\
In\ 1\ second\ he\ will\ run\ 2,5meters.[/tex]