If the original question is like this, it is a brain teaser. The soybean is gone because it has teeth. If the topic is changed to: the weight of soybean sprouts has increased by 4.5 times, and now there are 100 kilograms of soybean sprouts, then how many kilograms of soybean sprouts are made? Then the answer is:

100/(1+4.5) = 200/11,about18.2kg. 。