You need to make a set of five rods for a magic trick, with numbers on them ranging from 1 to 31 inclusive. Then you ask people to pick a number and show you only the top number of whatever rods it is on. From that you have to guess which number the person picked. This has to be done within a few seconds and isn't a matter of remembering what numbers are on them.

What numbers should be on each of the five rods?

(In reply to The top number? by Charlie)

Charlie, I follow your solution....

I certainly hope that your interpretation is not what Lewis intended... because then IMHO he should have been much more explicit and not used 'top', but rather the GREATEST or HIGHEST-VALUED number on each rod.

Ambiguity sux. :-)

Posted by SilverKnight on 2003-11-11 15:55:29