What number comes next in the series?

5 15 5 18 5 24 14 20 _

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?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

Can you name four days which start with the letter 'T'?

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?