Answer:
F = 12 N
Step-by-step explanation:
Mechanical Work
Mechanical work is the amount of energy transferred by a force. It's a scalar quantity, with SI units of joules.
Being F the force vector and s the displacement vector, the work is calculated as:
W = F.s
If both the force and displacement are parallel, then we can use the equivalent scalar formula:
W=F.s
When the value of the work is known and we need to find the force, we solve the above equation for F:

The wrapping present is moved by s=9 m doing W=108 J of work. The force used is:

F = 12 N