could you please explain how to solve it step by step?

Assume an investor has obtained at a cost of $200 the right to buy 100 Intel shares for $20.00 each. The party on the other side of the transaction has received $200 and has agreed to sell 100 Intel shares for $20.00 per share if the investor chooses to exercise the option. If the price of Intel does not rise above $20.00 before April 21, 2021, the option is not exercised and the investor loses $200. But if the Intel share price does well and the option is exercised when it is $30, what is the investor's gain after the initial cost is subtracted