this is actually Operation Research. Answer all plis im waiting

Suppose that the objective function is Maximize z = 2x1 + 3x2, and the constraint are X1 + 3x2 =0. The optimum solution is: Question 18 Not yet answered Marked out of 1.00 P Flag question Select one: a. X1 = 2 and X2 = 0 b. X1 =2 and x2 = 3 CC. X4 = 6/7 and x2 = 12/7 d. x1 = 12/7 and X2 = 67 - e. X4 = 0 and X2 = 2 Consider the transportation problem having the following parameter table Question 19 Not yet answered Marked out of 1.00 Destination P Flag question 1 2 Supply Source 2 8 6 5 4 4 2 Demand 3 3 According to the problem above, then a. There are no the true answer b. Using the north-west corner method, we strightly get optimum solution c. Using the least-cost method, we strightly get optimum solution d. Using the Vogel's Approximation Method, we strightly get optimum solution e. Using the least cost method, we found that the starting basic solution is the best, if we comparing with other method. Question 20 Not yet answered Marked out of 1.00 p Flag question A district in Papua province has 3 construction project plans that are being offered namely Project 1, Project 2, and Project 3. After going through the auction process finally 3 contractors were chosen (Contractor A, Contractor B and Contractor C) as the winner of the auction. The problem is which contractor will work on Project 1, Project 2 and Project 3 so that the total project construction costs are minimal. From the tender documents, it was found that Contractor A had offered a price of $100 million, $125 million and $140 million for Project 1, Project 2 and Project 3, respectively. Contractor B submitted a price offer of $150 million, $140 million and $125 million, while Contractor C offered a price of $135 million, $140 million, and $130 million respectively for Projects 1, 2 and 3. Assuming the volume of the three projects were the same, and quality standards guaranteed not to be violated, then how the assignment of the three contractors for the 3 project plans. Select one: a. A-3, B-2, C-1 b. A-3, B-1, B-2 c. A-1, B-, C-2 d. A-1, B-2, C-3 e. A-, B-1, C-3