Cheryl wishes to invest her inheritance of $200,000 so that her
return on investment is maximized, but she also wishes to keep her
risk level relatively low. She has decided to invest her money in
any of three possible ways: CDs, which pay a guaranteed 6 percent;
stocks, which have an expected return of 13 percent; and a money
market mutual fund, which is expected to return 8 percent. She has
decided that any or all of the $200,000 may be invested, but any
part (or all) of it may be put in any of the 3 alternatives. Thus,
she may have some money invested in all three alternatives. In
formulating this as a linear programming problem, define the
variables as follows: C = dollars invested in CDs, S = dollars
invested in stocks, M = dollars invested in money market mutual
fund. Suppose that Cheryl also decided that the amount invested in
money market must not exceed one-fourth of the total amount
invested. Which is the best way to write this constraint?

Select one:

a. – C – S +3 M ≤ 0

b. – 3 C – 3 S + M ≤ 0

c. – 3 C + S – 3 M ≤ 0

d. 3 C + S – M ≤ 0

e. C – S – 3 M ≥ 0