If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

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?

I have Rs.50 and I spend it in the way as below.

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

The more you take me, the more you leave me behind.
Who Am I?

Make a sentence consisting of three words that have the whole alphabet.

A blonde put eyeliner on her head. Why?

What kind of band never plays music?