How many times in a given day, minutes and hour clock comes in a straight line ?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

What is always in front of you but can’t be seen?

What's the only room from which no one can enter or leave

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

Can you spot the hidden girl in the picture below?

Can you identify the famous TV character from the rebus below?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?