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?

If eleven plus two equals one, what does nine plus five equal?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

The owner of a popular clothing store comes up with his own method of pricing items. A vest costs $8, socks cost $10, a tie costs $6, and a blouse costs $12. Using the owner’s method, how much would a pair of underwear cost?

I’m tall when I’m young, and I’m short when I’m old. What am I?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

People put me on the table and cut me but do not eat me. What am I?

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

What does this rebus means ?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?