Which word does the below Plexor means ?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?

What breaks yet never falls, and what falls yet never breaks?

What is at the end of a rainbow?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Different lights make me strange by changing me into different sizes. What am I?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

What is so fragile that saying its name breaks it?