If an object 70 millimeters high is placed 40 millimeters from a converging lens and the image is formed 120 millimeters in front of the lens on the same side as the object, what’s the height of the image?

The basic proportion we have to use is:

where  is the distance of the object from the lens (40 mm),  the distance of the image from the lens (120 mm),  the height of the object (70 mm) and  the height of the image (that we have to find). Solving for  we find

so, the height of the image is 210 mm.

Indoraptor for sure