What brings you down but never up?

Can you find out the remainder when 3^300 is divided by 5?

All of the flowers I have are orchids except two. All of the flowers I have are hibiscuses except two. All of the flowers I have are roses except two.

Can you tell me how many flowers I have?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

What has 88 keys?

Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
----------

You have three orange, two pink and five purple balls in the drawer beside your bed. There is no electricity and the room is entirely dark. How many balls must you take out to ensure at least one ball of each colour at least?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

How can I get the answer 24 by only using the numbers 8,8,3,3?

You can use the main signs add, subtract multiply and divide.

Which is Odd One Out and why?

4377

3954

9862

8454

9831