What has many keys but can’t open a single lock?

What is red and smells like blue paint?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not.

Is a married person looking at an unmarried person ?

Intelligence Agency need to break the vault but the problem is that they are not able to break the vault.

On the vault, a text is written as:

31 11 33 33 43 45
21 25
31 24 11 31 51 41

To Break the code Intelligence Agency brings a mathematician named Joseph.
Minutes later he deciphers the code.

Whats the code?

John, a 5-year-old boy, was really fond of the chocolates. He asked his Mother to give him some money to buy his favourite chocolates. His Mother gave him $45. He went to the shopkeeper and asked, "How much is one chocolate for?". The shopkeeper said $3 for one chocolate. Also, if you give me the wrappers of three chocolates, I will give you one for the exchange.
In total, how much chocolate could John eat?

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

What question can you never answer yes to?

A man dies of old age on his 25 birthday. How is this possible?

Prove that twice of ten is the same as twice of eleven.