THIS CONTAINS SOME BASIC QUESTIONS OF OPERATION RESEARCH

1. Department of Mathematics
Brainware Group of Institutions
Assignment-I (ME 705C)
1. Using graphical method to solve the following LPP :
Maximize 3 2
subject to 2 2
3 4 12
, 0
z x y
x y
x y
x y
 
 
 

2. Solve the following LPP by simplex method:
Maximize 3
subject to 3 2 3
2 2 2
, , 0
u x y z
x y z
x y z
x y z
  
  
  

3. Solve the following LPP by Big M method :
  
  
  

1 2 3
1 2 3
1 2 3
1 2 3
2 9
4 2 5
3 2 4
, , 0
Max z x x x
Subject to x x x
x x x
x x x
4. Find all the basic feasible solutions of the system
1 2 3
1 2 3
2 4 11,
3 5 14,
x x x
x x x
  
  
5. A manufacturer of patent medicine is preparing a production plant on medicines A and B.
There are sufficient ingredients available to make 20000 bottles of A and 40000
bottles of B,but there are only 45000 bottles into which either of the medicines can be put.
Furthermore it takes three hours to prepare enough material to fill 1000 bottles of A, it
takes one hours to prepare enough material to fill 1000 bottles of B and there are 66 hours
available for this operation.The profit is Rs. 8.00 per bottle of A and Rs. 7.00 per bottle of B.
Formulate this as a linear programming problem to maximize the profit.
6. Distinguish Between Transportation Problem and Assignment Problem.
7. Find the optimal solution and the corresponding cost of transportation in the following
transportation problem
D1 D2 D3 D4 Supply
O1 19 20 50 10 7
O2 70 30 40 60 9
O3 40 8 70 20 18
Demand 5 8 7 14

2. Department of Mathematics
Brainware Group of Institutions
8. The Head of the department has five jobs A, B, C, D, E and five sub-ordinates V, W, X, Y, Z.
The number of hours each sub-ordinates would take to perform each job is as follows:
V W X Y Z
A 3 5 10 15 8
B 4 7 15 18 8
C 8 12 20 20 12
D 5 5 8 10 6
E 10 10 15 25 10
How would the jobs be allocated to minimize the total time.
9. A firm makes two types of furniture – chairs and tables. The profit for each product as
calculated by the accounting department is Rs. 20 per chair and Rs.30 per table. Both
products are to be processed on three machines M1, M2, M3. The time required in hours by
each product and total time available in hours per week on each machine is as follows:
Machine Chair Table Available
Time(hrs)
M1 3 3 36
M2 5 2 50
M3 2 6 60
i) Give a mathematical formulation to this linear programming problem.
ii) Use the graphical method to solve this problem.
10. The owner of a small machine shop has four machinists available to assign to jobs for the
days. Five jobs are offered with expected profit for the each machinist on each job as given
in the table. Find the assignment of Machinists to jobs that will result in a maximum profit.
A B C D E
1 62 78 50 101 82
2 71 84 61 73 59
3 87 92 111 71 81
4 48 64 87 77 80

3. Department of Mathematics
Brainware Group of Institutions
11. Deduce the expression expected number of customers in the system and expected number
of customer waiting in the plane(i.e. queue length)
12. A project schedule has the following characteristics
1-2 1-3 2-4 3-4 3-5 4-9 5-6 5-7 6-8 7-8 8-10 9-10
4 1 1 1 6 5 4 8 1 2 5 7
Draw the project network and find the critical path.
13. A harbour has single dock to unload the containers from the incoming ships. The arrival
rate of ships at the harbour follows Poisson distribution and the unloading time for the
ships follows exponential distribution. The arrival rate and service rate are 8 ships per
week and 14 ships per week, respectively. Find the following:
i) Utilization of the dock.
ii) Average number of waiting ships in the queue.
iii) Average number of waiting ships in the system
iv) Average waiting time per ship in the queue.
v) Average waiting time per ship in the system.