Can you find out the missing number in the grid?

What is the below Rebus indicate?

Find the next number in the following series:
6, 14, 26, 98, __?

What goes up but never comes down?

I am the fastest animal but cannot climb the tree. What am I?

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?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

What is greater than gold but cannot be bought. it can never be sold and can earn if its sought. though it can be broken, it can still be fixed. for by birth it can't start nor by death it is ended.what am i?

How can a man go eight days without sleep?

With the help clues provided in the image, can you find the 5 digit key?