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?

Answer:The equation is P(L or S) = 0.3 + 0.2 - 0.15Step-by-step explanation:* Lets study the meaning of "or" , "and" on probability - The use of the word "or" means that you are calculating the   probability  that either event A or event B happened - Both events do not have to happen - The use the word "and" means that both event A and B have   to happen * The addition rules are: # P(A or B) = P(A) + P(B) ⇒ mutually exclusive (events cannot happen   at the same time) # P(A or B) = P(A) + P(B) - P(A and B) ⇒ non-mutually exclusive (if they     have at least one outcome in common) - The union is written as "A∪B" or "A or B"  - The Both is written as "A∩B" or "A and B" * Lets solve the question - The probability P(L) of a visitor riding its largest roller coaster is 30%∵ P(L) = 30% = 30/100 = 0.3 - The probability P(S) of a visitor riding its smallest roller coaster is 20%∵ P(S) = 20% = 20/100 = 0.2 - The probability of a visitor riding both roller coasters is 15%∵ P(L and S) = 15% = 15/100 = 0.15- To find P(L or S) lets use the rule of non-mutually exclusive ∵ P(A or B) = P(A) + P(B) - P(A and B) ∴ P(L or S) = P(L) + P(S) - P(L and S) - Substitute the values above to find the probability of a visitor riding   the largest or the smallest roller coaster∴ P(L or S) = 0.3 + 0.2 - 0.15 = 0.35∴ The probability of a visitor riding the largest or the smallest roller    coaster is 0.35* The equation is P(L or S) = 0.3 + 0.2 - 0.15