This is pretty much just arithmetic. There are 10 tons of watermelons and the are 99% water. That means they are (10)(.99)= 9.9 tons water, 0.1 tons "non-water". The melons "dry out", losing only water so that their water weight is 98% of their new weight. Let the weight of water lost, in tons, be "w". Then their total weight is 10- w and their water weight is 9.9- w. That is a ratio of . Solve for w. The new weight of the water melons is 10- w tons.