Here we need to calculate the income of this year.
We know that a year has 52 weeks. And, our payed weeks are 51, they are, the 50 weeks we work plus the one week of paid-vacation. The remaining week does not give us income, as is unpaid. So our total year income is:
51 * $615 = $31,365
So, our surplus will be our income minus our expenses:
