Recent Riddles & Brain Teasers

You are in a room with no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify which one is a magnet?

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

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?