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?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

When it's bad luck to meet a black cat?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

Check out the number list below and find what number comes next in the sequence.

111 , 113 , 117 , 119 , 123 , 137 , ?

How many letters are in the alphabet?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.