Help with this question, thanks.

Problem 1 A concavo-convex lens made of glass (n = 1.5) has surfaces of radii 20 cm and 60 cm. Object - 80 cm 160 cm (a) Locate the image of an object placed 80 cm to the left of the lens along the optic axis after only having passed through the first lens. (b) A similar lens is placed coaxially at a distance of 160 cm to the right of the first. Locate the final position of the image after the rays from the object have passed through both lenses. (c) Determine the overall magnification of the image