What work can one never finish?

I cannot talk, but I always reply when spoken to. What am I?

You have two jars of chocolates labelled as P and Q. If you move one chocolate from P to Q, the number of chocolates on B will become twice the number of chocolates in A. If you move one chocolate from Q to P, the number of chocolates in both the jars will become equal.

Can you find out how many chocolates are there in P and Q respectively?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

Which alphabet letter is a question?

There is a brick of gold and a brick of iron in a boat (both 10-inch blocks), if they are both dropped into the water which will make the water level higher?

Count the number of triangles in the below picture?

What seven-letter word has hundreds of letters in it?

You are driving down the road in your car on a wild, stormy night, when you pass by a bus stop and you see three people waiting for the bus

An old lady looks as if she is about to die.
An old friend who once saved your life.
The perfect partner you have been dreaming about.
Knowing that there can only be one passenger in your car, whom would you choose?

Can you name an animal whose killing cannot be performed without spilling your own blood?