Extending a winch handle

[sparkythecat]

I have a winch with a handle that is 300mm from the axis of the drum.
If I extend the length by 75mm, so that the distance between the handle and the axis of the drum is now 375mm, by what percentage, will I decrease the force necessary to turn the drum under the same load?

Is the answer 25%?

[sparkythecat]

Can you just expand on that a bit?
The radius of the drum at the start of the lift is 40mm and as the cable is wound onto the drum the radius will increase to 70mm at the end of the lift.