In the middle of a round pool lies a beautiful water lily. The water lily doubles in size every day. After exactly 20 days, the lily will cover the complete pool.

After how many days will the water lily cover half of the pool?

+1 vote

In the middle of a round pool lies a beautiful water lily. The water lily doubles in size every day. After exactly 20 days, the lily will cover the complete pool.

After how many days will the water lily cover half of the pool?

...