Questions

Vitamin K helps in clotting of blood. It is used by the body to help blood clot.

Warfarin (Coumadin) is used to slow blood clotting. By helping the blood clot, vitamin K might decrease the effectiveness of warfarin (Coumadin).

The rank of the different ministers is determined by the Prime Minister, according to whose advice the President appoints the Ministers [ Art 75(1) ] and also allocates business among them [ Art 77 ].

You have to actually count all the balls in the pyramid.
Simple way is to count the balls in each level.

So lower most level lets say 1st level has 4 x 4 balls; i.e. 16 balls
Similarly 2nd level has 3 x 3 balls; i.e. 9 balls.
3rd level has 2 x 2 balls; i.e. 4 balls.
The top most level has just 1 ball.

So the total number of balls is 16+9+4+1 = 30.

So the image has 30 Balls in all.

ptr pointer is constant. In ptr = yourbuf the program is trying to modify it, hence an error.