How much working capital does a corporation with $50 million in short-term debt and a current ratio of 4 have? Show work. Explain what working capital is used for. List three sources of working capital If a corporation sold X units of product for $Y each and had $M in total fixed and $L in total variable costs, write equations ( in X, Y, M, and L terms ) to find (a) its contribution margin, (b) its profit margin and (c) its break-even point (in units). You are a financial planner and have a client who would like to receive a $12,000 annuity for 25 years after retiring 20 years from now. Assuming an 8% return on investment can be earned prior to retirement and a 10% return can be earned after retirement, how much would you advise your client to invest annually, over the next 20 years, to achieve her retirement goal? Show your work and briefly explain your results