Question

The analysis of maximum daily rainfall on a city indicated that a depth of 300 mm has a return period of 60 years. The probability of one day rainfall depth equal to or greater than 300 mm in the city occurring exactly two times in 15 successive years is

• A. 1.981%
• B. 2.344%
• C. 4.325%
• D. 3.788%

Answer 1

The correct option is B 2.344%

$P=\frac{1}{T}=\frac{1}{60}$
$P_{\text{2 times in 15 years}}{=}^{15}{C}_2{\left(\frac{1}{60}\right)}^2{(1-\frac{1}{60})}^{13}$
$=0.02344=2.344$%