Can you place three balls such that the equation shown in the picture holds true?

Can you count the number of lines in the below picture?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

In the picture given below, can you find out which digit will take place of the question mark?

What's the best place to go shopping in the ocean?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

What kind of storm is always in a rush?

When you stop to look, you can always see me. But if you try to touch me, you can never feel me. Although you walk towards me, I remain the same distance from you. What am I?