Question

The probability that Ryan chooses Spanish is 0.86 and the probability that Riley chooses Spanish is 0.73. State the probability that:
a. they both chose Spanish
b neither of them choose Spanish
c. only one of them chooses Spanish
d. at least one of them chooses Spanish

Answer 1

a. If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events.

b. (1-.86)(1-.73) = ?

c. Either-or probabilities are found by adding the individual probabilities.

(1-.86) .73 = ?
OR
(1-.73) .86 = ?

d. This means one or both, so you need to add answers to a and c.