Lucy somewhere read: "Schoolbags can save the life. If you fell fully-clothed and with full schoolbag to the water, schoolbag could save life. You can catch it and it is hard to submerge it under water" She have doubts because of heavy books, notebooks and everything makes it heavy. So she decided to try it. One day right from school she went to the pool, still fully-clothed, boots and full school bag. In video you can see the result of her experiment.