...all but two are dandelions, all but two are roses and all but two are tulips?
Hint: I don't have very many flowers.
Answer: Three flowers.
I have a rose, a dandelion, and a tulip.
A lily pad starts in the middle of a pond on day 1, overnight it doubles in size. This happens every night. If the pond is covered on day 10, how big was the lily pad on day 9?
Hint: Work backwards, this way you don't need to know the size of the lily pad at the start.
Answer: 1/2 the size of the pond.
This is easiest to see by working backwards. On day 10 the pond is covered, so during the previous night it doubled in size.
Can you tell what this rebus is?
Hint: Say what you see.
Answer: Back to back.
[i.e. two back(s) - written back(wards)]