Noor observes the amount of helium in a balloon over time. She fills a balloon with 0.5 cubic feet of helium. During the first hour, the amount of helium decreases by 2.5% . During the second hour, the remaining amount of helium decreases by 3.25% . Which set of calculations can Noor use to determine the amount of helium in cubic feet remaining in the balloon at the end of the second hour? Responses
