What goes up but never comes down?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

How many triangles can you find in this given picture?

How do you go from 98 to 720 using just one letter?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

It's pretty hard to give up.
If you remove a part of it, you will be left with a bit.
Even if you remove another part, the bit still remains.
Remove one more and it still remains.

What is it?

This is a picture puzzle. You have to guess the name of the movie that can be related to the picture.

It spends most of its day eating white, but when it’s quick enough, it gets to eat fruit and sometimes some blue things. It’s in a dark room, where the walls are blue, it runs from a ghost that roams the halls and haunts it all the time. What is it?

Below rebus represent famous DiCaprio movie. Can you name it?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?