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.

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

Can you tell a 3D object that has just two surfaces?

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

Rearrange the letters in "new door" to make one word.

You walk into a room and see a bed. On the bed, there are two dogs, five cats, a giraffe, six cows, and a goose. There are also three doves flying above the bed. How many legs are on the floor?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

Why did Navjot Singh Sidhu put the new January calendar in the freezer

Do You See It?

10+10 and 11+11 can give you the same answer.

Explain how?