Me asap! could you explain how you got the answer

complete the two-way frequency table below, which shows the relationship between students who enroll in advanced algebra and physics in a particular high school. from a sample of 30 students, it is found that 19 are taking algebra, 12 are taking physics, and 4 are enrolled in both. how many students are enrolled in either algebra or physics?

algebra not in algebra total

physics 4

not in physics

total

a.) 27

b.) 23

c.) 3

d.) 4