It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

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 on the puzzle below?

A non-stop marathon is the shared favourite sport of three brothers.

*The oldest one is fat and short and trudges slowly on.
*The middle brother's tall and slim and keeps a steady pace.
*The youngest runs just like the wind, speeding through the race.

"He is young in years, we let him run!" the other two brothers explained, "'because though he is surely number one, he is second, in a way." Why is it?

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

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

What is wrong in the below Picture?

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

Something Extraordinary happened on May 6th 19778 at 12:34am what was that?

I’m orange, I wear a green hat and I sound like a parrot. What am I?