The level of radioactivity in the soil is decreasing by a factor of 1/2 each month
Answer:
15
Step-by-step explanation:
To find the minimum amount of items, x, that need to be sold for the manufacturer to make a profit, we can use the quadratic formula





In context of the problem, we can only rely on the positive value, as the negative value would lead to a loss of profit.

Furthermore, we must round to the nearest whole number, as you cannot make part of an item.
Lastly, if you were to plug in 14 into the equation for Profit, you would still have a negative number (i.e. a negative profit), thus requiring the manufacturer to make no less than 15 items to make a profit:

Over time, compound interest at any rate will outperform simple interest. When the rates are nearly equal to start with, compound interest will be greater in very short order. Here, it takes less than 1 year for compound interest to give a larger account balance.
In 30 years, the simple interest will be
... I = P·r·t = 12,000·0.07·30 = 25,200
In 30 years, the compound interest will be
... I = P·(e^(rt) -1) = 12,000·(e^(.068·30) -1) ≈ 80,287.31
_____
6.8% compounded continuously results in more total interest