In the following image we have two poles with heights of 80 cm and 50 cm. They are 180 cm apart each other and we have a light bulb hanging from the ceiling between them. The post with height 80 cm casts a shadow of 60 cm on the ground. The post with 50 cm casts a shadow of 30 cm on the ground. How high the light bulb is hanging above the floor? (the diagram is not draw to scale)
