An amusement park reports that the probability of a visitor riding its largest roller coaster is 30 percent, the probability of a visitor riding its smallest roller coaster is 20 percent, and the probability of a visitor riding both roller coasters is 15 percent.

which equation can be used to calculate the probability of a visitor riding the largest or the smallest roller coaster?

p(largest or smallest) = 0.30 - 0.20
p(largest or smallest) = 0.30 + 0.15 - 0.20
p(largest or smallest) = 0.30 + 0.20 - 0.15
p(largest or smallest) = 0.30 + 0.20