Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

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?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

There is a place where if I stand up straight, I will still be considered sideways.

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

John was a very careless driver, so his owner Jacob gave him an offer that he will get an incentive of Rs.30 for every bottle box he delivered without breaking it and he will be charged Rs.90 for every bottle box he broke. Jacob gave John 100 bottles-box to deliver. After delivery, Jacob paid John Rs.2400. How many bottles-box did John break?

What English word has three consecutive double letters?