The probability of a 10-year flood to occur at least once in the next 5 years is

Question

Question

This question was previously asked in

ESE Civil 2014 Paper 2: Official Paper

Answer 1

Concept:

The probability for the annual maximum flood magnitude to occur = \(\frac{1}{{Return\;period\;}} \)

Calculation:

\(\begin{array}{l} p = \frac{1}{T} = 0.1\\ q = 1 - p = 0.9 \end{array}\)

Probability of flood at least once in next 5 years

= 1 – no flood in next 5 years

= 1 – q⁵

= 1 – (0.9)⁵ = 0.409