Why is a river so rich ?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

It is always ahead of me yet I can never see it. What is it?

A thief is convicted in Mexico. He gets the death penalty. The judge allows him to say the last sentence to determine how the penalty will be carried out. If the thief lies, he will be hanged, if he speaks the truth he will be beheaded. The thief tells the last sentence and to everybody's surprise some minutes later he is set free because the judge cannot determine his penalty. What did the thief say?

A car meter reading shows 72927 miles a palindromic number.
what is the minimum number of miles you would need to travel to see another palindromic number on the car meter reading?

Can you replace the question mark with the correct number in the below table sequence?

What does this Rebus Picture means ?

What can you hold in your right hand, but never in your left hand?

What number comes next in the series?

5 15 5 18 5 24 14 20 _