Which alphabet letter is a question?

What four weights can be used to balance from 1 to 30 pounds?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

A man has to get a fox, a chicken, and a sack of corn across a river.

He has a rowboat, and it can only carry him and one other thing.
If the fox and the chicken are left together, the fox will eat the chicken.
If the chicken and the corn are left together, the chicken will eat the corn.

How does the man do it?

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Find the hidden panda in the image below.

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?