Answer: 32%
Step-by-step explanation:
The total number of students that signed up for chemistry and algebra
two is 386.
Let x represent the number of students that signed up for both chemistry and algebra two
If 209 students signed up for algebra two, then the number of students that signed up for algebra two only is
209 - x
If 300 need to have signed up for chemistry, then the number of students that need to have signed up for chemistry only is 300 - x
Therefore,
x + 209 - x + 300 - x = 386
- x + 509 = 386
x = 509 - 386
x = 123
If 123 students would be signed up for both courses, then the probability that a student chosen at random from the 386 will be signed up for both of the courses is
123/386 × 100 = 32%