Calculating Torque for a Gearbox and Flywheel with an Efficiency of 92%

[edz2012]

A gearbox and flywheel with a output shaft rotating in the opposite direction to the input shaft at 5 times it's speed. The gearbox has an efficiency of 92%
If the flywheel is solid has a mass of 50kg a diameter of 1.5m and is to accelerate from the rest to 300 revs min^-1 in 1minute

Can someone please show me how to calculate torque required at the input shaft please

 

[SteamKing]

Hint: output torque = input torque / gear ratio