In a compound microscope the distance between the objective and eyepiece lenses is 23.05 cm. The focal lengths of the eyepiece and objective lenses are 2.8 and 0.4 cm. What is the overall magnification for a person with a near point of 25 cm?

In order to heighten your enjoyment of your 29 carat blue diamond, you view it through a lens held close to your right eye at an angular magnification of 5.1. The distance of your right eye's near point is 25 cm.  What is the focal length f of the lens in centimeters? f = ?cm

A lens with a 0.98 meter focal length is placed right in front of a -3.6 meter focal length.  A small object is placed 1.6 m in front of the two lenses.  What is the magnification of the image formed by the two lenses?  The space between the lenses is minuscule.

The objective lens of a microscope is a planoconvex (flat on one side) lens that has a short focal length of 7.6 mm. The focusing knob on the microscope moves the object toward or away from the objective lens. The microscope is designed so that the object will be seen in focus through the eyepiece when the objective lens forms a real image of the object 160 mm behind the objective lens. (a) At what object distance in mm is the microscope focused? (b) What is the lateral magnification of the objective lens?(c) Account for the resulting image shown in the figure, i.e. using your calculations, justify that indeed the image is real, magnified, and inverted.