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

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

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

I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

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.

No one wants to have it, but if one got it, he does not want to lose it. What is It?

A guard is positioned at the one side of the bridge saying ‘A’. His task is to shoot all those who try to leave from ‘A’ to the other side and say ‘B’. He also need to welcome the person who comes from another side ‘B’ to his side ‘A’. The guard comes out of his post every 1 hour and looks down the bridge for any people trying to leave. You are at side ‘A’ and wish to go to another side ‘B’. you also know that it would take 1:45 hr to cross the bridge. How will you cross the bridge?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

What is the longest word in the dictionary?