I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

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?

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

Bay of Bengal is in which state?

If EELS + MARK + BEST + WARY = EASY

What does HELP + BARK + WARD + LEAD equal?

On a charity event in Russia, Murray beat Djokovic by winning six games and losing three games.
Note: There is a total of 5 service breaks(one who serve lost the game).
Who served first, Djokovic or Murray?

Complete the table series riddle by finding the number that can replace "??".