For 8 I got A and for 9 I got D. If you can double check my
answer that would be great but if not I mostly need help on 10. If
you can explain the process behind it so I can learn how to do it
myself that would help a lot. Once again thank you for your amazing
help.

Part 3. A company owns three factories on the
Washita River that emits four different pollutants. The state has
recently mandated at least a 22 ton reduction for each pollutant.
The company is considering the tonnage of emissions to process from
each factory that will reduce the amount of pollutants in the river
that meet state requirements for each pollutant. The company has
available processes for each factory effective in reducing the
pollutants but the cost and efficiency vary between factories as
illustrated in the table. For example, one ton processed by Factory
A will reduce pollutants 1,2,3,4 by 0.03, 0.04, 0.06, 0.02 tons
respectively at a cost of $360.

Question 8. What is the minimum cost that meets state
requirements?

(A) $170600   (B)
$172600   (C) $173600   (D) $171600  
(E) none of the above

Part 4. An international distribution company
of containers has operated a warehouse in Manila to service
customers between the Asian continent and the North American
continent for the past four years. Liann Able, VP of logistics,
calls the planning meeting to order and begins discussion on the
transportation plans to respond to recent changes in unit costs due
to cost adjustments within the different countries. The unit costs
of shipping from each source warehouse to each destination site,
the capacity (in thousands) of the warehouses, and the demand (in
thousands) of the destination sites are given in the table.

Question 9. What is the minimum total shipping cost in thousands
that satisfies the requirements?

     (A) $10640   (B)
$15870   (C) $11640   (D) $16190  
(E) none of the above

Burke Concrete Company produces concrete in a batch process.
Each batch is 2000 tons. The dry ingredients are cement, sand, and
gravel. The cement by weight makes up between 12% and 15% of a
batch and costs $55.95 per ton. Sand by weight costs $12.95 per ton
and must make up between 26% and 38% of a batch of the concrete.
Gravel costs $9.95 per ton and must make up between 32% and 52% of
a batch of the concrete. The amount of sand must never exceed
gravel in a batch. Each batch of concrete must contain exactly 90%
of cement, sand, and gravel. Define X=tons of cement in each 2,000
ton batch, Y=tons of sand in each 2,000 ton batch and Z=tons of
gravel in each 2,000 ton batch.

Question 10. What is the optimal daily ingredient mix for Burke
Concrete that minimizes cost?