I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

If eleven plus two equals one, what does nine plus five equal?

Which of the below owl is odd one out?

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

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

It belongs to you, but other people use it more than you do. What is it?

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?