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

There is a unique number which when multiplied by any number from 1 to 6, we will get the new number that contains the same digits only.

Can you find that number?

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

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

What can you deduce from the following BrainBat?

CRY
LMKI

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

What demands an answer, but asks no questions