Answer:
8.31 weeks
Step-by-step explanation:
Given that the cost of one share of Apple stock, C=$120
Rate is the increment of the stock value, R= 5%/week=0.05 / week.
Assuming that after t week, the stock has been sold for $180.
Since the stock value increased at 5% every week, so, the interest is compounded weekly, so


[taking log both sides]
weeks
Hence, after 8.31 weeks the stock has been sold for $180.