In order to increase the magnifying power of a compound microscope

Q. In a compound microscope the focal length of objective lens is $1.2cm$ and focal length of eye piece is $3.0cm$. When object is kept at $1.25cm$ in from of objective, final image is formed at infinity. Magnifying power of the compound microscope should be :

Q. The focal length of the objective of a telescope is 60 cm. To obtain a magnification of 20, the focal length of the eye piece should be

Q. A compound microscope has an objective of focal length 2 cm and eye piece of focal length 5 cm.The distance between two lenses is 25 cm. If final image is at 25 cm from the eye-piece. Then the magnifying power of the microscope.

Q. Focal length of objective of an astronomical telescope is 1.5 m. What should be the focal length of eye - piece to get the magnification of 25 times?

Q. Objective lens of a compound microscope produce magnification of 10. In order to get an overall magnification of 100 when image is formed at 25cm from eye, what should be the focal length of the eye piece?