Complete the table series riddle by finding the number that can replace "??".

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Which country gets ill every time?

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?

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

What is harder to catch the faster you run?

I taste better than I can smell. Who am I?