If there are \(m\) gallons of salt water that is\( m\%\) salt, how many gallons of water must be added to make a solution that is \(10\%\) salt?
(A)\(\frac { m - 10 } { 10 } \) (B)\(\frac { m^2 } { m - 10 } \) (C)\(\frac { m^2 - 10m } { 10 } \) (D)\(\frac { 10 } { m^2 - 10 } \) (E)\(\frac { m^2 - 10 } { m + 10 } \)
C