Answer: 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%