Question

The probability that a 100 years flood is equalled or exceeded, at least once in 100 years is

• A. 99%
• B. 64%
• C. 36%
• D. 1 %

Answer 1

The correct option is B 64%

$\text{Risk}=1-(1-P{)}^{100}$

$=1-{(1-\frac{1}{100})}^{100}=0.634\simeq 64\%$