A 3-in-diameter solid steel shaft, used as a torque transmitter, is replaced with a 3-in hollow shaft

Question:

A 3-in-diameter solid steel shaft, used as a torque transmitter, is replaced with a 3-in hollow shaft having a ¼ -in wall thickness. If both materials have the same strength, what is the percentage reduction in torque transmission? What is the percentage reduction in shaft weight?