ETP...PET...Equal Time Point...Point of Equal Time....MAY also be referred to as CP ...Critical Point.... in the Exam, I hope they will only refer to the PET....

PSR:

Time to PSR = EH/(O+H) .....where E = safe endurance

then to find the distance .... distance = (time to PSR) x Outbound GS

PET:

Distance to PET = DH/(O+H) ....where D = sector distance

then to find the time .... time = Distance/speed Out