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

You can hear me, but you can't touch or see me.

What am I?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

Manish and Manoj play 5 games of chess.
Both Manish and Manoj win the exact same number of games. There is no tie at all.

How?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

When is the top of a mountain similar to a savings account?

Why is a river so rich ?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

Outside a tattoo artist's shop, there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?