Questions

One reason the skeletal system is important is because the skeletal system creates the connective tissue and tendons that allow the body to move.

Antarctica is surrounded on all sides by water. The Indian, Pacific and Atlantic Oceans surround it on all sides. These three Oceans all meet at Antarctica. The three oceans are collectively called the Southern Ocean.

This is the area located south of 50° latitude.

First nationalisation of commercial banks in India took place in 1969 and second time in 1980.

From the hints,

Only two options for 1st and 2nd digits => 4,2 and 9,3 since it is single digits

Sum of second and third digit  = 10 

If 2 => 3rd digit = 8

If 3 => 3rd digit = 7

4th digit = 2nd digit + 1 => (2+1 =3) or (3+1 = 4)

Sum of all digits = 30

Let 5th digit be x

=> 1st possibility = 4 + 2 + 8 + 3 + x = 30 => x = 13 (Not possible since it has 2 digits)

=> 2nd possibility = 9 + 3 + 7 + 4 + x = 30 => x = 7

Therefore, the PIN is 93747 

The letter 'E'.

As of the above given data,

It is in the 1st place in Earth, 2nd in Heaven and in the middle of the Sea.

It appears once in a Year and twice in a Week.

It is present in February, June, September, October, November & December.

But not in the Month.

Hence, it is the letter 'E'.