You can brute-force the first part (obv the answer is .5), and the second part is probably looking for you to use the central limit theorem on the sum to get the answer. So, you'll calculate the expected profit, the variance, get a Z-Value for the required value of the sum to end up above 80,000(or equivalently the needed average to end up above 80), bust out the table, and find the probability of ending up above that.