Frequency of exceedance any peak exceeding is . Its complement, is the probability of exceedance, the probability that has been exceeded at least once by time . This probability can be useful to estimate whether an extreme event will occur during a specified time period, such as the lifespan of a structure or the duration of an operation. If is small, for example for the frequency of a rare event occurring in a short time period, then Under this assumption, the frequency of exceedance is equal to the probability of exceedance per unit time, , and the probability of exceedance can be computed
Unit of alcohol down) about one unit of alcohol per hour, although this may vary depending on sex, age, weight, health, and many other factors. The number of UK units of alcohol in a drink can be determined by multiplying the volume of the drink (in millilitres) by its percentage ABV, and dividing by 1000. For example, one imperial pint (568 ml) of beer at 4% alcohol by volume (ABV) contains: <br> <br> The formula uses . This results in exactly one unit per percentage point per litre, of any alcoholic beverage. The formula can be simplified for everyday use by expressing the