Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

I have teeth but i don't bite. Who Am I ?

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

What word is pronounced the same if you take away four of its five letters?