45 is wrong, 46 is right

50 is wrong

Use the following scenario and data for questions 41 to 50 A car dealership decided to add an annex to its sales office as a customer lounge. The project is divided into the activities listed in the following table. The immediate predecessor(s), times and costs, both normal and crashed, are given. To finish the project sooner, the dealership has to make time and cost tradeoffs. If the project needs to be finished in 25 weeks, you are required to formulate a linear programming model to decide about how much to crash for each activity. Activity Immediate Predecessor(s) A B C D E F G H . A B, C C D E F, G Time (weeks) Normal Crashed 5 3 7 4 6 4 7 5 8 4 8 5 5 3 6 3 Cost ($) Normal Crashed 1800 2400 2500 4300 3200 4600 2700 3500 3300 3800 2300 2900 4200 4700 2400 3300 To answer the following questions, you may want to use the last column of the following table to compute the cost of crashing an activity by one week. Activity Immediate Predecessor(s) Cost/Week A B D E F G H A A B, C C D E F, G Time (weeks) Normal Crashed 5 3 7 4 6 4 7 5 8 4 8 5 5 3 6 3 Cost ($) Normal Crashed 1800 2400 2500 4300 3200 4600 2700 3500 3300 3800 2300 2900 4200 4700 2400 3300 QUESTION 45 Which of the following is a good constraint to model the fact that activity A is an immediate predecessor of activity C? XA-X-YC26 O-XA+Xc+V656 o-XA+X+ VC26 OXA+x 5 25 X;20,y; 20 for all i = A,B,C,D,E,F,G min 300x4+600x8 +700xc +400xp +125x 3 +200x: +250x6 +300x s.t IV VATN 13+ya IV -24 -X Xc+Yc 6 IV IV -33 IV -*c -Xc IV 00 +x+yD +x+yo +x2 + x + xy + y -X - -D 8 IV IV + X6 + yo 5 6 + xy + y + x + y 2 -XG 6 y. $ 2 tu 3 VC VI VI 2 VD s 2 ya s 4 ya VI 3 yo s 2 . 3 VA 2 H 25 x, 20, y, 20 for all i = A,B,C,D,E,F,G min 300 yA + 600 73 +700c + 400 yp +125y3 + 2007: +250 yg +300 y: V sit 5 -X 18+ IV IV 6 -*3 IV IV 7 Xc+Yc + XD + YD -xc + x +YD -xc +xg+ yg -XD +x+y -X -XF IV 00 2 8 A + XG+ YG IV 6 O -NG + xy + y 2 +xhty: 2 S 6 Y. 2 tu $ Yc VI YD s y's s 4 3 3 YG S 2 V . x, 20. y, 20 for all i = A,B,C,D,E,F,G min 300 yA +600 y3 + 700yc +400yp +125yx+ 2007: +250 yg +300 y: sit 5 -A IV IV IV -44 6 IV 7 Xc tych + XDYD -xc +x+yo -Xc -XD 7 +x3 + x IV IV TV 8 + xy + y 8 - X5 +xg+Yo 5 IV IV 6 + Xx + y +x+y o -XG 6 ya A VIVI 2 V3 3 c VI 2 YD 2 VE VI VI 4 3 VG 2 VI VM VH 3 25 X, 20. y, 20 for all i = A,B,C,D,E,F,G O none of the above