Analytical Reasoning
Analytical Reasoning presents a set of constraints - linear or circular seating, grouping, scheduling, blood relations, direction sense, ranking - from which one arrangement or a small number of answers follows. The method is fixed: symbolise every constraint, start with the most restrictive, and test each option against all constraints.
Method
- Convert each sentence into a compact rule, including negatives such as not adjacent and not at an end.
- Draw slots and fill the most constrained item first.
- In circular arrangements, fix the facing direction: facing the centre, left is anticlockwise; facing outward, left is clockwise.
- Blood relations: draw a family tree marking gender and generation, and never assume gender from a name or role.
Worked example
Five people P, Q, R, S, T sit in a row facing north. R is at one end. Q is immediately to the right of P. S sits between Q and T. T is not adjacent to R.
If R is at position 1, T cannot be at position 2. The pair P, Q can occupy positions 2 and 3, which places S at 4 and T at 5, or positions 3 and 4, which leaves no room for S between Q and T. So the order is R, P, Q, S, T. Placing R at position 5 conflicts with T not being adjacent to R.
Traps
- Ignoring immediately, which fixes adjacency, versus between, which may not.
- Reversing left and right when the group faces outward.
- Assuming a person is male or female from the name or role.
- Building one arrangement and stopping before checking for a second valid solution.
- Missing a constraint hidden in a phrase such as not at either end.