What does this rebus riddle means ?

Women do it once a year after they turn 19 but men get to do it only once in a lifetime. What is it?

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

How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

10+10 and 11+11 can give you the same answer.

Explain how?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

A horse was tied to a rope 5 meters long and the horses food was 15 meters away from the horse. How did the horse reach the food?

If you drop a 15 kg iron bar and a 5 kg bag of cotton from a height of 50 meters which will reach the ground first?