What work can one never finish?

John Went to the nearby store in a Mall to buy something for her home. Below is the conversation between the two:

John: How much for the one?
Shopkeeper: It is $2
John: How much for the Eleven?
Shopkeeper: It is $4
John: How much for the Hundred?
Shopkeeper: It is $6.

What is John buying?

Who always enjoys poor health?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99