Hi,
when doing a market sizing question, most solutions soley rely on households, e.g. when calculating the number of cars/light bulbs sold (https://www.preplounge.com/de/bootcamp.php/case-cracking-toolbox/identify-your-case-type/market-sizing)
But what about the commercial segment? There are company cars and many many commercial buildings, which use light bulbs, as well. How would you approach this? Can you simplify this by saying "I believe there are an additional 10% of company cars" or "For every light bulb in the private segment, there is another one in the commercial one"?