Q197 · Practice questionTechnology-activeComplex familiar5 marks
QUESTION 197 (5 marks)
In a tournament A beats B, B beats C and C beats A. Define if i beats j and 0 otherwise, in order A,B,C. There are no draws.
a)[2 marks]
Write D and its square.
b)[3 marks]
Compute its cube and interpret its diagonal. Are these self-victories?
WORKED SOLUTION
5 marksPractice marking scheme
ANSWER
(a) ; . (b) ; closed routes, not self-victories.
Worked solution
(a) The row-to-column convention gives D as stated. Two-step routes are A-C, B-A and C-B, yielding the stated square.
(b) A third step completes each cycle, so . For example A-B-C-A is one length-three route from A back to A. The entry counts a route, not a match where A defeats itself; D itself still has zero diagonal.
Equivalent mathematically justified methods accepted.
Exact answers unless a decimal accuracy is specified.
Part a: Use the stated convention to write D.
Part a: Calculate its square.
Part b: Compute D cubed.
Part b: Interpret the closed three-step routes.
Part b: Distinguish route counts from observed self-victories.
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