An object is placed on the principal axis of convex lens of focal length \( 10 \, \text{cm} \) as shown. A plane mirror is placed on the other side of lens at a distance of \( 20 \, \text{cm} \). The image produced by the plane mirror is \( 5 \, \text{cm} \) inside the mirror. The distance of the object from the lens is ______ \( \text{cm} \).
