Answer
The distance to the back of the head appears to be $~~10~m$
Work Step by Step
The light rays from the back of the head travel $3.0~m$ to the far mirror, $5.0~m$ to the near mirror, and then $2.0~m$ to the eyes.
The total distance is $10~m$
The distance to the back of the head appears to be $~~10~m$
