In a simple microscope,if the final image is formed at infinity,what will be its magnifying power?

In a compound microscope,the intermediate image is generally .......

$A$ microscope consists of an objective of focal length $1.9 \,cm$ and an eyepiece of focal length $5 \,cm$. The two lenses are kept at a distance of $10.5 \,cm$. If the image is to be formed at the least distance of distinct vision, the distance at which the object is to be placed before the objective is (least distance of distinct vision is $25 \,cm$). (in $\,cm$)

In a compound microscope,let $u_0$ and $v_0$ be the object distance and image distance respectively. The objective of focal length $f_0$ magnifies a tiny object into a real,inverted image. The linear magnification of the objective is

The angular magnification of a simple microscope can be increased by increasing

$A$ convex lens of focal length $12.5 \ cm$ is used as a simple microscope. When the image is formed at infinity,the magnification is . . . . . . . (Near point for normal vision is $25 \ cm$)