Final answer:
The half-life of a drug that decays by about 30% each hour is approximately 2 hours, as after two hours, roughly half of the drug would remain.
Step-by-step explanation:
To determine the half-life of a drug that decays by about 30% each hour, we need to calculate when it will have 50% of the original amount remaining. Starting with 100% and decreasing by 30% each hour, after the first hour we would have 100% - 30% = 70% of the drug left. After two hours, it would decay another 30% of the remaining amount (70%), which is 21%, leaving us with 70% - 21% = 49%.
Thus, after about two hours, we are very close to the half-life, since approximately 50% of the drug remains. Therefore, the nearest whole number to the calculated half-life is 2 hours.