Neco 2019 Commerce Question 6

An electronic retailer advertises a television as "energy‑efficient", claiming it saves \(15\%\) on annual electricity consumption compared with a standard model that uses \(150\) kWh per year. The buyer pays a marked price of \(M\) naira. The retailer adds a hidden surcharge of \(5\%\) on the marked price and then applies a \(10\%\) discount on the resulting amount. The buyer therefore pays \(120\,000\) naira. The actual electricity consumption of the purchased TV is measured at \(138\) kWh per year. Electricity costs \(30\) naira per kWh. The warranty covers only manufacturing defects, not mis‑representation. (a) What is the actual percentage saving in electricity? (b) What was the marked price \(M\)? (c) What is the total monetary loss to the consumer, consisting of the over‑payment on the TV price plus the monetary value of the shortfall in electricity saving? Express your answer in naira, rounded to the nearest naira.