Answer:
5:3:2
Step-by-step explanation:
see image
Jarek gets half. Then from the other half, Jerzy gets 3 pieces of 5 and Justyn gets the leftover 2 pieces. But Jarek's piece is all 5 pieces of the first half.
Jarek 5 parts:
Jerzy 3 parts:
Justyn 2 parts
5:3:2
see image