Data Sufficiency

For every additional item she buys, the total price will be one additional cent less than a round number of dollars. So if she buys one item, the total price will end in .99, if she buys two items it will end in .98, and so on. So if the price ended in .72, she must have bought 28 items (she can't have bought 128 items or more, because she spent less than $50). So Statement 1 is sufficient. Statement 2 is not sufficient, so the answer is A.