Before Mount Everest was discovered, what was the highest mountain in the world?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

Which wheel of car does not rotate when you turn your car right?

Check out the number list below and find what number comes next in the sequence.

111 , 113 , 117 , 119 , 123 , 137 , ?

You have to put a letter on the following to make it a meaningful word. The only challenge is that you can't use 'E'.

S E Q U E N C _

Take number 1000 and then add 20 to it.
Now add 1000 one more time.
Now add 30.
Now add 1000 one more time.
Now add 40.
Now add 1000 one more time.
Now add 10.

What is the total?