What is so fragile that saying its name breaks it?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

Which is the rope you never skip with?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

What has 88 keys?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

By using 'because' continuously three times, can you make an English statement ?

You along with your friend are standing in front of two houses. Each of those houses inhabits a family with two children.

Your friend tells you the below two facts:
1) On your left is a family that has a boy who likes accounts but the other child loves science.
2) On the right is a family with a seven-year-old boy and a newborn baby.

You ask him, "Does either of the family have a girl?"

To this, he replies, "I am not quite sure. But can you guess that? If you are right, I will give you $500."

Which family do you think is likely to have a girl?