The Lily Pad Pond

A lily pad doubles in size every day. If on the 60th day the pond is filled with the lily pad.

On what day is the pond only half covered?

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The Frog And The Well

A frog is at the bottom of a 30 meter well.

Each day he summons enough energy for one 3 meter leap up the well. Exhausted, he then hangs there for the rest of the day.

At night, while he is asleep, he slips 2 meters backwards.

How many days does it take him to escape from the well?

Please Note: Assume after the first leap that his hind legs are exactly three meters up the well. His hind legs must clear the well for him to escape.

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