Answer:
36.5625
Explanation:
so, if it decays at a rate of 7.5% every 2 days, and we have 234 hours, we do the following, 234/24, since there are 24 hours in a day, that gives us 9.75, "7.5% every 2 days" so we do this, 9.75/2 = 4.875
4.875 * 7.5 = 36.5625
i migt be wrong, but i'm pretty sure this is the answer, i'm not saying this is the answer like some people do, please let me know if i'm wrong.