Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

Can it be possible to build a house that has all its four walls facing towards the South?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

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

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

Can you identify the Oscar-winning movie from the rebus below?

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

A man desired to get into his work building, however he had forgotten his code.
However, he did recollect five pieces of information
* Fifth number + Third number = 14
* The fourth number is one more than the second number.
* The first number is one less than twice the second number.
* The second number and the third number equals 10.
* The sum of all five numbers is 30.

What is the code ?

A boy collects white seashells from the sea and brings them home every night. When he has enough of them, he decides to sell them to a trader.

The trader is ready to buy the shells and he asks the boy about the quantity. At this, the boy starts calculating. He has a giant box that contains 3 mini boxes. Two of them have another mini box inside. If the giant box can hold 50 shells, how many brown shells can he sell to the trader?