<prompt> Human: I have 40K in undergrad loan debt. Im going to grad school in the fall. Grad school costs 40K over two years. I was just approved for a 20K grad school loan to cover the first two of four semesters in grad school.I have 20K in the bank.Should I use this 20K to pay down my undergrad loan debt which is subsidized and will not accrue interest while Im in school? Or should I pay cash for the first year of grad school? Or should I take out a loan for grad school and invest the 20K somewhere else?  <response>: It all depends on the interest rates! 