Question

take the largest image distance and calculate the focal length of the lens used.

 

Ques:

Take the largest image distance and calculate the focal length of the lens used. image distance = 226 mm object distance =100 mm focal length = ??? What is the magnification of a mirror in which the size of the image is 24 cm and the size of the object is 4 cm?  How do you find the focal length??