Question

The probability of a flood in any given year in a region prone to floods is 0.2. What is the probability of flooding, at least once in four years?

Answer 1

I make it about 0.59 ....

Explanation:

...this is one MINUS the probability that it DOESN'T flood in any year of the 4 year period.

So, this is `1 - 0.8^4 = 1 - 0.41 = 0.59` (I've rounded the numbers...)

GOOD LUCK