Pipe Bursting

The pipe having outer radius(ro), inner radius(ri), and thickness (t), the pipe is called as thick cylinder, when
The pipe having outer radius(ro), inner radius(ri), and thickness (t), the pipe is called as thin cylinder, when
Working pressure is the minimum pressure a pipe may be subjected to while in-service. (Say True or False)
A pipe has outer radius of 24mm, inner radius of 20mm,then the pipe is
The stress used to compute bursting pressure in this experiment is