Answer
20 students will take biology, 10 take Integrated Science and 10 take both
Explanation:
With Venn diagrams it's best you work from the inside out. With that in mind we know 10 students take both Biology and Integrated Science. In Biology there are 30 total students including the ones that also take both sciences. So we subtract the ones that take both and get 20 students taking only biology. After that there's 30 students total, subtract that from 40, the total number of students and you get 10, the amount of students who take Integrated Science