An office block is 270 meters high and each floor has a height of 3 meters. The base of the office block is a square which is 50 meters on each side. Half way up, the office block becomes narrower, with a horizontal cross-section which is a square that is 30 meters on each side. Each office has floor area a square 5 meters by 5 meters. Make a sketch of the office block. How many offices are there? number of offices =