What begins with T, ends with T, and has T in it?

What does this rebus mean?

O
N
C
E
TIME

I am an odd number. Take away a letter and I become even. What number am I?

10+10 and 11+11 can give you the same answer.

Explain how?

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

During an experiment, a guy throws a bouncy ball from a 100 feet tall building. The ball has a specific characteristic. Every time it hits the ground, it bounces up halfway.

How many bounces do you think the ball will make before it comes to a stop ?

Why Wine Glass Stem is so long?

What does below chemistry rebus means?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?