Can someone help me solve this problem?

The parabola opens: y=√x-4 (principal square root) up down right left

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.

There are 18 female students and 16 male students in a class. which of the following expresses the ratio of female students to male students in simplest form? а) 10 b) 9 to 8 c) 8: 9 d)18/16