What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

How many triangles are there on the puzzle below?

You see me once in June, twice in November, and not at all in May. What am I?

How is the moon similar to a dollar?

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?

Which English verb becomes past tense just by rearranging the letters?

What is always in front of you but can’t be seen?

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?

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

Can you count the number of lines in the below picture?