Question

A bi-convex lens with the focal length of 25 cm and a meniscus concave lens with the focal length of 10 cm, separated from each other as much as 70 cm. An object is located 100 cm from the bi-convex lens along the optical axis. Find out the location of ultimate image create by the combination of these two, using both algebra and roughly by ray tracing method. Also figure out the total magnification.