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

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

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?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

Make a sentence consisting of three words that have the whole alphabet.

In a certain bank, a man deposits a certain amount. According to the bank policies, the amount will be doubled up in a year but as the service charge, they will also deduct Rs. 65 by the end of every year.

If after the 6th year, the amount becomes 0, what do you think is the original amount he deposited in the bank?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

What does below rebus means ?