There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

Which number should replace the question mark?

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

What always comes into a house through the keyhole?

John has played 50 ODI's and his average is 50. How many runs should he score in his 51st ODI, so that his average score jumps to 51?

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

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

Replace the question mark with the number below given a simple math problem.