I have teeth but i don't bite. Who Am I ?

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

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

Can you write down eight eights so that they add up to one thousand?

I have Rs.50 and I spend it in the way as below.

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

What is it?

John was born on March 5, 1970, in Delhi, India. Jacob was born 25 days before John. The year when they took birth, Republic Day fell on Monday.

Can you find out on what day was Jacob born?

What can you see in the middle of March and April that you can never see in any other month?

What is black when you buy it, red when you use it, and gray when you throw it away?