Fri Sep 18, 2020
Approach to solve:
Where to start:
1.- A and D are selected in the team (from condition 3), which means that the two members of group I are already selected and we need to select 3 members from group II. From condition 5, we can say that X will be in the team (A is selected then X is also selected). Y and Z cannot be selected (Y cannot be selected because among A, D, E and Y only 2 can be in the team and we already selected A and D; Z cannot be selected as C is not in the team (condition 6)). We are left with U, V and W. We need to select two among U, V and W so we can have three cases.
2.- Next we select A and E from A. D. E and Y. A and E belong to group I and so we need three more from group II. X will be one of them (condition 5). Now, since E is in the team either one of U or W can be in the team (condition 4). Y and Z cannot be in the team because of the reason explained in previous point. Therefore, we have two options. U and V or W and V.
5. Next, we select D and Y. D is from group I and Y from group II. One more from group I can be B or C. Similar to the third case when we selected A and Y but here we are not restricted to the selection of X alone as there is no A. X will be in some of the teams but not in all teams. With C in the team, Z will also be in the team but V cannot be in the team (condition 1). With B in the team, neither U nor V can be in the team so we should select X and W.
6. Last case is with E and Y selection. With E in the team, either U or W can be in the team. From group I we can select either B or C. Rest of the case is similar to the last case.
Did we miss any case? No. How can we be so sure? Because we discussed all the 6 cases coming out of condition number 3. Any team would include exactly two among A, D, E, Y and we made a case for all possible combinations. This is a much better practice, as it would avoid any confusion related to number of cases possible. We should always check subcases for further combinations with each member one by one. Following a flow diagram surely helps in determining the combinations with given restrictions. When there is no such condition which gives us any concrete information related to number of cases, we should go with the approach involving least number of cases.
Phone: +91 903 903 4 903,