Nowadays, there is a huge requirement of bandwidth and mobility to end users. For fulfilling this, Fiber-Wireless (FiWi) networks are designed consolidating the advantages of both optical and wireless networks. Optical networks provide high bandwidth and stability while wireless networks provide cost efficiency and mobility. In FiWi networks Optical Network Units (ONU) placement is a very important issue since ONU links both optical and wireless end of the network. Reducing ONUs in the network directly leads to cost efficiency of that network. For the same purpose, we implement an algorithm based on teacher phase of Teaching Learning Based Optimization (TLBO). The implemented algorithm reduces required ONUs in the network.