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

Which tank will fill first?

Find the next number in the series below

21 32 54 87 131 ?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

A Shopkeeper sold a few chickens to four different customers on a particular day. It was such that each customer purchased half of the remaining chickens and half the chicken more.

Can you find out how many chicken were sold by the shopkeeper on that day if we tell you that the fourth customer bought a single chicken ?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Find the missing letter in the last circle logically in the given below picture.

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?