Please write down constrains and solve it by excel solver

A company must meet the following demands for cash at the beginning of each of the next four months: month1, $120; month2, $170month; month3, $140; month4, $230. At the beginning of month 1 the company has $350 in cash and $210 worth of bond1, $220worth of bond2; and $190 worth of bond 34 The company have to sell some bonds to meet demands, but the penalty will be charged for any bonds sold before the end of month 4. The Penalties for selling $1 worth pf each bond are as shown in the table below. The penalties have to be paid in cash, Bond 1 0.75 Months of Sale 2 3 0.6 0.9 0.95 0 0.6 0.55 1 2 3 4 0.85 0 0 0.5 WN 0.9 What is the minimal cost(i.e. the sum of all penalities paid) of meeting cash demands for the next four month? (Fractions of bonds can be sold) k