Answer:
![Px = \frac{[(N*P) +(N*P*M1]/N}{1+ M2}](https://tex.z-dn.net/?f=Px%20%3D%20%5Cfrac%7B%5B%28N%2AP%29%20%2B%28N%2AP%2AM1%5D%2FN%7D%7B1%2B%20M2%7D)
And if we replace we have this:

So then the highest the stock price can go before you receive a margin call if the maintenance margin is 40 percent is $ 46.86.
See explanation below.
Explanation:
For this case we define the following notation:
N= 500 represent the number of stocks for JAsper
P = 41 represent the stock price
M1 = 60% = 0.6 represent the initial margin
Px represent the highest stock price the variable of interest for this case
M2= 40% or 0.4 represent the mainteneance margin
We can find the value of Px with the following formula on this case:
![Px = \frac{[(N*P) +(N*P*M1]/N}{1+ M2}](https://tex.z-dn.net/?f=Px%20%3D%20%5Cfrac%7B%5B%28N%2AP%29%20%2B%28N%2AP%2AM1%5D%2FN%7D%7B1%2B%20M2%7D)
And if we replace we have this:

So then the highest the stock price can go before you receive a margin call if the maintenance margin is 40 percent is $ 46.86.