Corp Fin Q from CFA Text

Anyone do problem 12 p. 75 in corp fin section 28? Clearly I am doing something wrong…any help out there? Operating Cash Flow ((Revenue -Operating Cost - Depreciation) (1-T)) + Depreciation (50 - 50) (1-.3) + 50 = 50? They get 85

just figured it out

EBIT is 50. So no need to deduct depreciation any more. EBIT(1-T) = NI = 50 (0.7) = 35 add back depreciation = 35 + 50 = 85