What is the leading coefficient of the polynomial?

23x5 + 12x2 + 19x3 + 15x6
a) 12
b) 15
c) 19
d) 23

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.