What is the next number in this matchsticks series riddle?

Next Number in the Series,

5, 16, 49, 104, ?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

How can a man go eight days without sleep?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Can you find out who is the kidnapper in below Picture and why, Explain ?

What can go up a chimney down, but can’t go down a chimney up?

Use the digits from 1 up to 9 and make 100.

Follow the rules.
=> Each digit should be used only once.
=> You can only use addition.
=> For making a number, two single digits can be combined (for example, 4 and 2 can be combined to form 42 or 24)
=> A fraction can also be made by combining the two single digits (for example, 4 and 2 can be combined to form 4/2 or 2/4)

Question: how can we do this?

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?

What is at the end of a rainbow?