What would be the magnification if you were using a 40x objective

A microscope is an instrument which is used to see the objects which are tiny and difficult to observe through naked eye. The microscope magnifies these objects and enlarge their size. It has two lenses that are ocular and objective.

The magnification for 10X ocular lens and the 40X objective lens is expected to produce the total magnification of 400X (10 x 40 = 400).