Physics

The key is recognizing that the object distance and focal length determine the image type through one simple rule: when the object sits between the focal point and center of curvature ($f < d_o < 2f$), light rays converge after reflection to form a real, inverted image on the same side as the object. Since $15\,\text{cm}$ falls exactly in this zone (between $10\,\text{cm}$ and $20\,\text{cm}$), you can predict all three properties without the mirror equation—real images from concave mirrors are always inverted, and this particular position produces magnification greater than 1.

The key is recognizing that the object distance and focal length determine the image type through one simple rule: when the object sits between the focal point and center of curvature ($f < d_o < 2f$), light rays converge after reflection to form a real, inverted image on the same side as the object. Since $15\,\text{cm}$ falls exactly in this zone (between $10\,\text{cm}$ and $20\,\text{cm}$), you can predict all three properties without the mirror equation—real images from concave mirrors are always inverted, and this particular position produces magnification greater than 1.