100 students are interviewed to see which of biology, chemistry or physics they prefer. 36 of the students are girls. 15 of the girls like biology best.
14 of the boys prefer physics.
7 out of the 31 who prefer chemistry are girls.
What percentage of the students prefer biology?

41%

Step-by-step explanation:

15 girls prefer biology.

Find the boys who prefer biology;

There are 36 girls in total so;

= 100 - 36

= 64 boys interviewed

14 boys prefer Physics

= 64 - 14

= 50 boys prefer Biology and Chemistry

7 out of the 31 who prefer chemistry are girls so the boys who prefer chemistry are;

= 31 - 7

= 24 boys

Boys who prefer Biology;

= 50 - 24

= 26 boys

Total who prefer biology;

= 15 girls + 26 boys

= 41 students

Percentage = 41/100 = 41%

4 and 5)16.97 or 12√2

6)15.59 or 9√3

7)y = 15.59 or 9√3     x =27

8)17.80