Puzzles — Mains Strategy

Mains Strategy

These written tasks are reasoning practice for objective CSAT. They do not imply a descriptive Mains paper in this subject. The purpose is to show how an arrangement follows from the clues and why alternatives fail. Begin by defining the slots and translating the most restrictive clue. Then present the few necessary cases in a clear order.

For the four-day example, explain why each early placement of the D–B block forces C onto Thursday. This makes the rejection auditable and shows why the remaining placement is unique. Merely writing A, C, D, B gives the answer without teaching the method. A final check should explicitly revisit A before C, D immediately before B and the restriction on C.

For possibility-versus-necessity exercises, use a witness or counterexample suited to the claim. Two valid arrangements with different B positions disprove that B must be second, while their shared A position may establish a necessary conclusion. Keep the logical force of the conclusion aligned with the evidence rather than overstating what one example proves.