5. A compound lens consists of two bi-convex lenses of focal lengths 10 cm and 20 cm, separated by a distance of 5 cm. (a) What is the effective power of the combination? (b) Locate the two principal points. (c) If an object is located 8 cm from the first lens, find the "principal" object and image locations. (d) Locate the image from the second lens. (e) Find the magnification.

5. A compound lens consists of two bi-convex lenses of focal lengths 10 cm and 20 cm, separated by a distance of 5 cm. (a) What is the effective power of the combination? (b) Locate the two principal points. (c) If an object is located 8 cm from the first lens, find the "principal" object and image locations. (d) Locate the image from the second lens. (e) Find the magnification.