In this work we present an analysis on the types of question from the first ten tests of the Brazilian Olympics of Astronomy and Astronautics (OBA). This paper examines the formulation of unique answer questions in the Astronomy issues, trying to point out elements for the elaboration of questions based on the rationalization of the answers, i.e. the linking of knowledge and not the simple placement of data to be substituted in previously memorized equations. The questions were classified according to closed problems or unique answer questions criteria, which are the basic skills necessary for students to use the time to resolve them. The ways to get the right result, the questions were classified as: direct knowledge (type 1), calculation (type 2), reasoning and knowledge (type 3), understanding (type 4) and questions of Science technology and society (type 5). It is observed through the editions of OBA that the types of questions tend to appear in all level tests. In each level the type 3 and type 4 questions, claims the same percentage, however, there is a percentage reduction on type 1. The number of questions that use the simple memorization of responses in High School has decreased over time as well. For example, in the I OBA questions of simple memorization there was a 32.4% and 53.3% in II OBA, but in the test of the IX OBA the percentage was 10% and there is still a reduction of 2.9% from the IX to the X OBA. The classification and the detailed of the results are presented showing that the questions of OBA, wherever possible, have converged to more questions of the 3 and 4 types and less on questions of type 1. In the initial series of tests, the percentage of simple memorization questions, or type 1 decreased from 77.8% in VII OBA to 35.7% in the X OBA. The largest difference in percentage occurred in the 5th to 8th series (eight years scheme) or 6th to 9th series (9 years scheme) of Elementary School, where the percentage reduced from 35.7% to 5.6%, since the VII to the X OBA. [ABSTRACT FROM AUTHOR]