I am a prime number.
The double of myself is equal to the square of me.

which number am I?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

How many triangles are there on the puzzle below?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

Using Only Five 5's and any mathematical operator make sum as 37

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

In a town, there are four houses located at different distances from each other. Following are the distances:

The third house is 60 meters apart from the first house.
The fourth house is 40 meters apart from the second house.
The third house is 10 meters nearer to the fourth house than it is to the second house.

Can you find out the distance between the fourth and the first house?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?