Given: The magnification +2.0 of a concave mirror of radius of curvature 60.0 $\text{ cm}$.Focal length $=\;\frac{60}{2}=-30$(-ve is taken because the focus of the mirror is behind the pole.) Magnification, $m=\;\frac{-v}{u}$Putting the value of magnification in the above formula we get,$\;\frac{-v}{u}\;=2$$v\;=-2 u$$v$ is image distance, $u$ is object distance and $f$ is focal length.Since,$\;\frac{1}{u}+\;\frac{1}{v}=\;\frac{1}{f}$Putting the values$\;\frac{1}{u}+\;\frac{1}{-2u}\;=\;\frac{1}{-30}$$\;\frac{1}{2u}\;=\;\frac{1}{-30}$$u\;=-\;\frac{30}{2}\text{ cm}$$u\;=-15\text{ cm}$Hence, the object distance is $-15\text{ cm}$.