Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

See the given image carefully. What you have to do is move the blue checkers in the position of the black checkers and vice versa. You are only allowed to move the checker to an adjacent empty space. Do it in the least possible moves.

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

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

What is the fastest way to double your money?

We have arranged an array of numbers below. What you have to do is use any kind of mathematical symbol you know excluding any symbol that contains a number like cube root. You can use any amount of symbols but you have to come up with a valid equation for all of them.

0 0 0 = 6
1 1 1 = 6
2 + 2 + 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

Who is that with a neck and no head, two arms and no hands? What is it?

Can you count the number of triangles in the given figure?