Download past MJSO past papers from here:

2017: MJSO task 1 from http://sciencecentremalta.net/wp-content/uploads/2018/10/mjso-booklet-task-1.pdf

2017: MJSO task 2 from http://sciencecentremalta.net/wp-content/uploads/2018/10/mjso-booklet-task-2.pdf

2017: MJSO task 3 from http://sciencecentremalta.net/wp-content/uploads/2018/10/mjso-booklet-task-3.pdf