Good Riddles

Question: A man wants to start a forest fire.There are 80 trees and you have a lighter. How many trees should he burn?

Question: What key is playful?

Question: Peter is hiding but his head is can seen.

Question: At low tide 14 rungs of a ship are above the water, the rungs are 15 centimeters apart. each 15 mins the water rises 15 centimeters. after 2 hours and 30 mins how many rungs are above the water?

Question: There has just been a heavy snowfall, Jeff goes out side and finds that there is twice as much snow in his garden as his neighbour's Kate but Jeff doesn't seem surprised.Why?