I need the answer as soon as possible

B/ Two shafts, a hollow and a solid, have the same length of 2 m and outside diameter of 35 mm and both can carry the same torque and have equal twisting angle. If the first shaft subrogated the second, so what is the measurement of the inner diameter of the first one? And what is the ratio of their torsional rigidities? Knowing that modulus of rigidities for hollow and solid shafts are 95 GPa and 30 GPa, respectively (15 Marts)