81 x 9 = 801. What must you do to make the this equation true?

There was a greenhouse.
Inside the greenhouse, there is a white house.
Inside the white house, there is a red house.
Inside the red house, there are lots of babies.

What is It?

What number do you get when you multiply all of the numbers on a telephone's number pad?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

Identify the 10 differences between the two given pictures.

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

Remove two matchsticks to make the below equation correct.

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?