A man dies of old age on his 25 birthday. How is this possible?

Prove that the below maths equation is true.

8 + 8 = 91

There’s a girl who has a large family. She has an equal amount of brothers and sisters, but each brother only has half as many brothers and sisters. What’s the correct amount of brothers and sisters?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

What are the 50th, 63rd and 100th numbers in the sequence below?
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...

As a whole I am both
safe and secure.

Behead me and I become
a place of meeting.

Behead me again and I am
the partner of ready.

Restore me, and I become
the domain of beasts.

What am I?

Only one color, 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?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'