International Mathematical Olympiad selection process Olympiad. Although in principle students of the lower levels may be selected to go to the IMO, it generally takes many years before they can compete with students of the highest level or nivel superior. After the National Competition the twenty best students of each level are invited to the June Training Session where students undergo the IMO selection process. "Hrvatsko matematičko društvo" invites about 20 contestants who performed best at the national level (national level competition is separated by age) to the Croatian Mathematical Olympiad ("Hrvatska matematička olimpijada", HMO) which consists of 2 days, 4 problems each. The best
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