Step-by-step explanation:
The total number of people mentioned in this problem is 15. 15 will be the denominator for the probability in fraction form. The sum of the # of people that include lifeguards and managers will be the numerator.
Therefore, the probability that the person picked is either a manager or a lifeguard is 10/15 [because there are 2 managers and 8 lifeguards; 2 + 8 =10].
Fraction form of probability: 10/15
Decimal form: 0.6 repeated
Percent form: about 66.67%