The administrator of a $200,000 trust fund must adhere to following guidelines. a. The money may be invested in three different types of securities: a utilities stock paying a 9% dividend, an electronics stock paying a 4% dividend, and a bond paying 5% interest.
b. The amount invested in the stocks cannot be more than half the total amount invested; the amount invested in the utilities stock cannot exceed $40,000; and the amount invested in the bond must be at least $70,000.
c. The total amount need not be fully invested at any one time.

Required:
Setup an LP problem to maximize profit.

Step-by-step explanation:

let us give all the quantities in the problem variable names.

x= amount in utility stock  

y = amount in electronics stock  

c = amount in bond

“The total amount of $200,000 need not be fully invested at any one time.”

becomes

x + y + c ≤ 200, 000,

Also

“The amount invested in the stocks cannot be more than half the total amount invested”

a + b ≤1/2 (total amount invested),

=1/2(x + y + c).

(x+y-c)/2≤0

“The amount invested in the utility stock cannot exceed $40,000”

a ≤ 40, 000

“The amount invested in the bond must be at least $70,000”

 c ≥ 70, 000

Putting this all together, our linear optimization problem is:

Maximize z = 1.09x + 1.04y + 1.05c

subject to

x+ y+ c ≤ 200, 000

x/2 +y/2 -c/2 ≤ 0

              ≤ 40, 000,

              c ≥ 70, 000

a ≥ 0, b ≥ 0, c ≥ 0.

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.