P(Success) = (1/1000) 1-P = (999/1000)
Say Mark wins +699 Dollars if Success else Mark wins -1 Dollars
now say he does this 200 times how much money will he have?
$$\sum\limits_{i=1}^{200} 699 * \frac{1}{1000} + -1 * \frac{999} {1000}$$
Is this the proper way to answer the question?
The result says he will lose 60 dollars (i.e -60)
As far as I know, expected values work like this:
Let's say I want to have $50$ babies. Very excited and all, and now I want to know how many boys I will have. Intuition tells me that, since the probability is $50\%$, I will have an expected value of $25$ boys and $25$ girls (the expected number is $np$, as you may already know).
Now I want to know my net profit. Let's say I spend $\$1,000$ on each girl (toilet paper expenses). However, I earn about $\$5,000$ from each boy I have (make them work young). What would my net profit be?
$$E=(5000)(25)+(-1000)(25)=\$100,000$$
I multiplied the expected value by the net profit to find the expected amount.
Now to your question, let's find the expected values first. Expected value is modeled as $np$, as shown above. Hence:
$$\text{# of successes: } \frac{1}{1000} * 200=\frac{1}{5}$$ $$\text{# of failures: } 200-\frac{1}{5}=199\frac{4}{5}$$
Just multiply the number of successes or failures by the net amount you get for each, and that will give you your expected net amount:
$$\therefore E=(+699)(\frac{1}{5})+(-1)(199\frac{4}{5})=-\$60$$