PREVIOUS TEST
Links:
http://www.ioaastrophysics.org/question-papers/
http://www.ioaastrophysics.org/wp-content/uploads/2019/09/IOAA_Q_2018-min.pdf
http://www.ioaa2019.hu/questions-and-solutions/
http://www.ioaastrophysics.org/wp-content/uploads/2019/09/IOAA_Q_2016-min.pdf
http://www.ioaastrophysics.org/wp-content/uploads/2019/09/IOAA_Q_2018-min.pdf