An electric dryer consumes 6 joules of energy when operating at 220 volts for 3 minutes. during operation the dryer draws a current of approximately?

Well, firstly 6 joules is a very low number for a dryer (impossibly low).  But here is how you'd do it with a more realistic number:
Energy is the power consumed multiplied by the time over which it is consumed:



This power is current time voltage



As you can see this current is very low by any household appliance standard, let alone an energy-hungry dryer!  Are you sure it's not something more like 
6×10⁵ J for the energy?

Efficiency is an act of doing something