Answer
Oxidation state of Br in $BrO_{3}^{-}$ is +5 and in $BrO_{4}^{-}$, it is +7
Work Step by Step
Net oxidation state of $BrO_{3}^{-}$ ion is -1, hence:
O: -2 x 3 = -6, hence Br should have oxidation state of +5
Net oxidation state of $BrO_{4}^{-}$ ion is -1, hence:
O: -2 x 4 = -8, hence Br should have oxidation state of +7
