IN a recent maths test five statements were labelled A to E. Statement A was “it is an odd two-figure number” and statement C was “it is a two-figure number which is an odd perfect square”. The other three statements (whose order I forget) were:
“it is a two-figure prime”
“it is a two-figure number which is the sum of two consecutive numbers” and
“it is a two-figure number with one odd digit and one even”.
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Candidates who chose an easy question were given a particular two-figure number and asked to tick which applied:
A is true B is true C is true D is true E is true
For those whose chose a hard question the boxes had the following different headings and the candidates were asked to tick the box or boxes which were always true:
B implies C C implies D D implies E E implies A A implies B
The box or boxes which should be ticked were the same for both questions.
What was statement D and which of statements A-E were true in the easy question?
A £10 book token will be awarded to the sender of the first correct answer opened on Thursday 9 March. The Editor’s decision is final. Please send entries to: Enigma 808, New Scientist, King’s Reach Tower, Stamford Street, London SE99 0BB.
