How can you make number one disappear by adding something to it?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

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

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

In the Mexico City area, there are two Houses H1 and H2. Both H1 and H2 have two children each.
In House H1, The boy plays for Mexico Youth academy and the other child plays baseball.
In House H2, The boy Plays soccer for his school in Mexico and they recently have a newborn.

Can you prove that the probability of House-H1 having a girl child is more than that of House-H2?

What number do you get when you multiply all of the numbers on a telephone's number pad?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

A kind heart person buy packed food at 3$/packet from United states and sells them at 1$/packet at Africa. After some time he becomes a millionaire.

How come the guy become millionaire ?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

If EELS + MARK + BEST + WARY = EASY

What does HELP + BARK + WARD + LEAD equal?