If f(12) = 100(0.50)^12, which expression gives f(x)?
A) f(x) = 0.50x
B) f(x) = 100x
C) f(x) = 100(x)^12
D) f(x) = 100(0.50)^x

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.