Help Gear Ratios !!!!!!! Help

[sanddrag]

I really got myself confused and I need some help.

For example....

Everthing on shafts is affixted to drive (e.g. pin, key, weld)
Say a motor has 5Nm torque.
There is a 10 tooth gear on the output shaft of this motor called "shaft A".
It drives a 40 tooth gear on another shaft called "shaft B"
Would the torque output by this last shaft be 20Nm?

Also, lets say there was also a 10 inch diameter wheel on "shaft B"
What torque would the wheel place on the ground??? for driving the robot.

I hope you know what I mean. If not ask a specific question so I can try to help you further understand my questions.

Thanks for the help.