A question about the Work Principle?

Question

According to it..

A machine can do up to twice the amount of work put into it

A machine cannot save effort or time

A machine does the same amount of work as is put into itl

Answer 1

the answers are all very vague. If I had to pick one, I'd pick 3.

Although more correct is

A machine does less than the amount work as is put into it

in order for #3 to be correct, the machine has to perform at 100% efficiency, which is not possible.