Spanish Biology Olympiad experiences in this field. This competition has always included both practical and theoretical examinations. In Spain the first National Biology Olympiad was organised in the Canary Islands by a group of high school teachers. By that time the Community of Madrid and the Community of Valencia had already celebrated their Regional Olympiad for four or five years. Currently, local phases are held in all the national autonomous communities, including Ceuta and Melilla, and the Spanish centres abroad. The Spanish Biology Olympiad is registered under number 585 939, Group 1, Section 1 in the National Registry of Associations of the Ministry
Return period interest and formula_5 is the counting rate. If the return period of occurrence is 1 in 234 years (formula_5 = 0.0043) then the probability of no occurrence in ten years is In a given period of "n" years, the probability of a given number "r" of events of a return period formula_5 is given by the binomial distribution as follows. In the limit of :formula_11, such that formula_12 then Take where Given that the return period of an event is 100 years, So the probability that such an event occurs "exactly once" in 10 successive years is: Return period is