Which main region of the human ear contains the ear canal?

Explanation:

Human ear consists of 3 parts i.e. inner ear, middle ear and outer ear. The function of outer ear is to collect the sound from the surroundings and this collected sound is passed through auditory canal.

The function of middle ear is to amplify vibrations several times. The vibrations gets converted into electrical signals in inner ear.

Auditory canal or ear canal is a path which is running from the  outer ear to the middle ear. The main function of ear canal is to send sound from the pinna to eardrum.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.