What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

How many triangles are there in the picture below?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

There is something which you can be arrested for attempting but not for successfully completing.

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

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?

What does the below mathematical rebus mean?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

A man is found hanging dead from the ceiling of a room. The room’s dimensions are 15 x 15 x 15. The man is only 6ft tall and the rope was only 2ft long. There are no windows and only one door to the room. The door is bolted shut from the inside, and a puddle of water is under the man. How did he kill himself?