- All, who neither dance on tight ropes nor eat peanut butter, are tall.
- Creatures with spikey hair who look silly will go swimming if they do not dance on tight-ropes.
- A kangaroo looks silly wearing sunglasses.
- A smart creature will always do what he ought to do.
- No one ought to go swimming who looks silly and eats peanut butter.
- A smart driver wears sunglasses.
- Kangaroos that have sneezing fits are avoided.
- Short creatures who go driving have sneezing fits.
- No creatures ought to dance on tight-ropes if they have sneezing fits.
- All, who do not dance on tight-ropes and who are avoided, have spikey hair.
Therefore, no short kangaroos who are smart...
(In reply to re: answer
Thanks DJ, we now have a clear contradiction in the 2 swimming rules if the kangaroos drive. They 'will' swim (statement 2) but, being smart will always do what they ought to do (statement 4) and therefore simultaneously wont swim (5).
To avoid the contradiction, the smart short kangaroos do not drive.