What is the below Rebus indicate?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

Can you name four days which start with the letter 'T'?

There was a strange boy who was born before his father. How can this be possible?

Can you fill the blank with the correct number?

6 30 870 756030 _____

Why is 6 afraid of 7?

Why do Chinese men eat more rice than Japanese men do ?

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?