What word begins and ends with an E, but has only one letter?

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

Can you fill the blank with the correct number?

6 30 870 756030 _____

How can you leave a room with two legs and return with six legs?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Two friends decide to get together; so they start riding bikes towards each other. They plan to meet halfway. Each is riding at 6 MPH. They live 36 miles apart. One of them has a pet carrier pigeon and it starts flying the instant the friends start traveling. The pigeon flies back and forth at 18 MPH between the 2 friends until the friends meet.

How many miles does the pigeon travel?